Playback apparatus, playback method, and program

ABSTRACT

A playback apparatus plays back data from a recording medium having recorded thereon a file system representing association between identification information for identifying a file and a position where the file is recorded, pieces of segment data constituting the file, and markers for the respective pieces of segment data, each marker that is recorded after a key marker specified in certain cases including location information of the key marker. The playback apparatus includes a detector that detects a last marker in a recording area where data has been recorded on the recording medium but has not been reflected on the file system, and a restoration processor that executes a restoration process of reflecting on the file system segment data that has been recorded on the recording medium but has not been reflected on the file system, based on the location information of the key marker and the location information of segment data.

CROSS REFERENCES TO RELATED APPLICATIONS

The present invention contains subject matter related to Japanese PatentApplication JP 2004-244398 filed in the Japanese Patent Office on Aug.24, 2004, the entire contents of which are incorporated herein byreference.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to playback apparatuses, playback methods,and programs. More specifically, the present invention relates to aplayback apparatus, a playback method, and a program with which datarecorded on a recording medium can be read even when a process ofrecording data on the recording medium was not completed normally.

2. Description of the Related Art

As recording media for recording video data captured by digital videocameras, for example, magnetic tapes or optical discs are used. Whenvideo data captured (and audio data collected) (hereinafter, video dataand audio data will be collectively referred to as AV data) is recordedon a recording medium on which AV data is managed using a file system,such as an optical disc, compared with a case where the AV data isrecorded on a magnetic tape, advantageously, it is possible to startplaying back the AV data from a desired point more quickly.

The file system is recorded on the optical disc after the recording ofthe AV data on the optical disc has been completed, and it includes filenames of the AV data, information representing positions where the AVdata is recorded on the optical disc, and so forth.

The files of AV data or the like recorded on the optical disc aremanaged based on the file system. For example, when the data is playedback from the optical disc by a playback apparatus, the playbackapparatus, with reference to the file system, obtains the file names ofone or more files recorded on the optical disc, the positions where therespective files are recorded on the optical disc, and so forth. When auser instructs playback of a file of interest, the position where thefile is recorded is identified based on the file system, and AV data andthe like constituting the file is read from the recording position andis then played back.

The AV data or the like is not necessarily recorded at a singlerecording position, and is in some cases distributed to a plurality ofrecording positions on the optical disc. In such cases, all theplurality of distributed recording positions associated with the singlefile is recorded in the file system. Thus, even when a file of AV dataor the like is recorded in a plurality of recording areas in adistributed manner, the entire AV data or the like that is recorded in adistributed manner can be read based on the file system. This isdescribed, for example, in Japanese Unexamined Patent ApplicationPublication No. 11-88821.

SUMMARY OF THE INVENTION

However, in recording apparatuses that have been available, such asdigital video cameras, when power supply is interrupted while AV data isbeing captured and recorded on an optical disc or immediately after theAV data has been captured, for example, due to the battery beingdetached by mistake, it could occur that a file system corresponding tothe data that has been recorded ends up unrecorded. In this case, evenwhen an attempt is made to play back the data from the optical discafter the power is recovered, the recorded AV data is not recognized andis not played back.

A possible approach for avoiding this situation would be to update thefile system each time a predetermined amount of AV data is recorded onan optical disc. Usually, however, the file system and AV data or thelike are recorded at remote positions on an optical disc. Thus, when thefile system is updated frequently, the pickup for writing on the opticaldisc is considerably moved frequently. This causes seeking sound, andincreases the ratio of seeking time in a series of recording periods sothat the efficiency of recording is decreased.

The problem described above is also anticipated in cases where dataother than AV data is recorded on optical discs.

It is desired that it is possible to read data recorded on a recordingmedium even when a process of recording data on the recording medium wasnot completed normally.

According to an embodiment of the present invention, there is provided aplayback apparatus for playing back data from a recording medium havingrecorded thereon a file system representing association betweenidentification information for identifying a file and a position wherethe file is recorded, a plurality of pieces of segment data constitutingthe file, and markers for the respective pieces of segment data, eachmarker that is recorded after a key marker specified in certain casesincluding location information of the key marker. The playback apparatusincludes detecting means for detecting a last marker in a recording areawhere data has been recorded on the recording medium but has not beenreflected on the file system, the last marker being a marker that isrecorded at an end of the recording medium in a recording process; andrestoration processing means for executing, for each of the pieces ofsegment data constituting the file, a restoration process of reflectingon the file system segment data that has been recorded on the recordingmedium but has not been reflected on the file system, based on thelocation information of the key marker and the location information ofsegment data, these pieces of location information being included in thelast marker detected by the detecting means.

The key marker is specified, for example, when the size of a marker hasreached a predetermined upper limit.

The restoration processing means may read a marker specified as the keymarker from the recording medium based on the location information ofthe key marker on the recording medium, and execute the restorationprocess based on the location information of the segment data, includedin the marker read, and based on the location information of the segmentdata, included in the last marker.

The detecting means may detect the last marker by executing binarysearch in the recording area where data has been recorded on therecording medium but has not been reflected on the file system.

Each of the markers may include a first number of times representing thenumber of times of rewriting in a recording area where the marker isrecorded on the recording medium, and when a marker is detected in therecording area where data has been recorded on the recording medium buthas not been reflected on the file system, and the detecting means maydetermine whether the marker is the last marker based on the firstnumber of times included in the marker and a second number of timesrepresenting the number of times of rewriting in the recording areawhere the marker is recorded on the recording medium, the second numberof times having been reflected on the file system.

Each of the markers may include first date and time informationcorresponding to a date and time of recording of the marker on therecording medium, and when a marker is detected in the recording areawhere data has been recorded on the recording medium but has not beenreflected on the file system, the detecting means may determine whetherthe marker is the last marker based on the first date and timeinformation included in the marker and second date and time informationcorresponding to a date and time of updating of the file system.

Each of the markers may include location information of the associatedsegment data recorded on the recording medium.

According to another embodiment of the present invention, there isprovided a playback method for playing back data from a recording mediumhaving recorded thereon a file system representing association betweenidentification information for identifying a file and a position wherethe file is recorded, a plurality of pieces of segment data constitutingthe file, and markers for the respective pieces of segment data, eachmarker that is recorded after a key marker specified in certain casesincluding location information of the key marker. The playback methodincludes the steps of detecting a last marker in a recording area wheredata has been recorded on the recording medium but has not beenreflected on the file system, the last marker being a marker that isrecorded at an end of the recording medium in a recording process; andexecuting, for each of the pieces of segment data constituting the file,a restoration process of reflecting on the file system segment data thathas been recorded on the recording medium but has not been reflected onthe file system, based on the location information of the key marker andthe location information of segment data, these pieces of locationinformation being included in the last marker detected.

According to another embodiment of the present invention, there isprovided a program for allowing a computer to execute a process ofplaying back data from a recording medium having recorded thereon a filesystem representing association between identification information foridentifying a file and a position where the file is recorded, aplurality of pieces of segment data constituting the file, and markersfor the respective pieces of segment data, each marker that is recordedafter a key marker specified in certain cases including locationinformation of the key marker. The process includes the steps ofdetecting a last marker in a recording area where data has been recordedon the recording medium but has not been reflected on the file system,the last marker being a marker that is recorded at an end of therecording medium in a recording process; and executing, for each of thepieces of segment data constituting the file, a restoration process ofreflecting on the file system segment data that has been recorded on therecording medium but has not been reflected on the file system, based onthe location information of the key marker and the location informationof segment data, these pieces of location information being included inthe last marker detected.

According to these embodiments of the present invention, a last marker,i.e., a marker that is recorded at an end of a recording medium in arecording process, is detected in a recording area where data has beenrecorded on the recording medium but has not been reflected on the filesystem, and for each of a plurality of pieces of segment dataconstituting a file, segment data that has been recorded on therecording medium but has not been reflected on the file system isreflected on the file system based on key-marker location informationand segment-data location information included in the last markerdetected.

According to another embodiment of the present invention, there isprovided a playback apparatus for playing back data from a recordingmedium having recorded thereon a file system representing associationbetween identification information for identifying a file and arecording position of the file on the recording medium, a plurality ofpieces of segment data constituting the file, and markers for therespective pieces of segment data, each of the markers at leastincluding location information of the associated segment data recordedon the recording medium, each of the markers being specified as a keymarker when the size of the marker has reached a predetermined upperlimit, and each marker that is recorded after the marker specified asthe key marker further including location information of the key markeron the recording medium. The playback apparatus includes detecting meansfor detecting a last marker in a recording area where data has beenrecorded on the recording medium but has not been reflected on the filesystem, the last marker being a marker recorded last on the recordingmedium in a recording process; storage means for storing the locationinformation of the key marker on the recording medium and the locationinformation of segment data recorded on the recording medium, thesepieces of location information being included in the last markerdetected by the detecting means; and salvage means for executing, foreach of the pieces of segment data constituting the file, a salvageprocess of reflecting on the file system segment data that has beenrecorded on the recording medium but has not been reflected on the filesystem, based on the location information of the key marker on therecording medium and the location information of the segment datarecorded on the recording medium, these pieces of location informationhaving been stored in the storage means.

According to this embodiment of the present invention, a last marker,i.e., a marker that is recorded at an end of a recording medium in arecording process, is detected in a recording area where data has beenrecorded on the recording medium but has not been reflected on the filesystem, and for each of a plurality of pieces of segment dataconstituting a file, segment data that has been recorded on therecording medium but has not been reflected on the file system isreflected on the file system based on key-marker location informationand segment-data location information included in the last markerdetected.

According to these embodiments of the present invention, even when aprocess of recording data on a recording medium was not completednormally, it is possible to read data that has been recorded on therecording medium.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a diagram showing an example of area segmentation on anoptical disc on which audio data and video data is recorded by arecording and playback apparatus according to an embodiment of thepresent invention;

FIGS. 2A to 2C are diagrams for explaining annulus data;

FIG. 3 is a diagram for explaining relationship between annulus data andsalvage markers;

FIG. 4 is a diagram for explaining relationship between annulus data andsalvage markers;

FIG. 5 is a diagram showing a directory structure that is used to managefiles of data recorded on an optical disc;

FIG. 6 is a diagram showing a directory structure that is used to managefiles of data recorded on an optical disc;

FIG. 7 is a block diagram showing the construction of a recording andplayback apparatus according to an embodiment of the present invention;

FIG. 8 is a diagram showing an example of information included in asalvage marker;

FIG. 9 is a diagram showing an example of information included innon-volatile-memory information;

FIG. 10 is a flowchart of a recording process;

FIG. 11 is a flowchart of a salvage-marker generating process;

FIG. 12 is a diagram for specifically explaining the recording process;

FIG. 13 is a diagram for specifically explaining the recording process;

FIG. 14 is a diagram for specifically explaining the recording process;

FIG. 15 is a diagram for specifically explaining the recording process;

FIG. 16 is a diagram for specifically explaining the recording process;

FIG. 17 is a diagram for specifically explaining the recording process;

FIG. 18 is a diagram for specifically explaining the recording process;

FIG. 19 is a diagram for specifically explaining the recording process;

FIG. 20 is a diagram for specifically explaining the recording process;

FIG. 21 is a flowchart of a disc handling process;

FIG. 22 is a flowchart of a disc handling process;

FIG. 23 is a flowchart of a quick salvage process;

FIG. 24 is a diagram for specifically explaining the quick salvageprocess;

FIG. 25 is a diagram for specifically explaining the quick salvageprocess;

FIG. 26 is a flowchart of a full salvage process;

FIG. 27 is a flowchart of a last-salvage-marker detecting process;

FIG. 28 is a diagram for specifically explaining the last-salvage-markerdetecting process;

FIG. 29 is a diagram for specifically explaining the full salvageprocess;

FIG. 30 is a diagram for specifically explaining the full salvageprocess;

FIG. 31 is a diagram for specifically explaining the recording process;

FIG. 32 is a diagram for specifically explaining the recording process;

FIG. 33 is a diagram for specifically explaining the quick salvageprocess;

FIG. 34 is a diagram for specifically explaining the quick salvageprocess;

FIG. 35 is a diagram for specifically explaining the full salvageprocess; and

FIG. 36 is a diagram for specifically explaining the full salvageprocess.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

Now, embodiments of the present invention will be described. Thecorrespondence between the aspects of the present invention described inthis specification and embodiments of the present invention is, forexample, as follows. This description is intended to assure thatembodiments supporting the aspects of the present invention described inthis specification are described in this specification. Thus, even if anembodiment in the following description is not described as relating toa certain aspect of the present invention, that does not necessarilymean that the embodiment does not relate to that aspect of the presentinvention. Conversely, even if an embodiment is described herein asrelating to a certain aspect of the present invention, that does notnecessarily mean that the embodiment does not relate to other aspects ofthe present invention.

Furthermore, this description should not be construed as covering allthe aspects of the present invention described in this specification.That is, the description does not deny the existence of aspects of thepresent invention that are described in this specification but notclaimed in this application, i.e., the existence of aspects of thepresent invention that in future may be claimed by a divisionalapplication, or that may be additionally claimed through amendments.

A playback apparatus according to an embodiment of the present inventionis a playback apparatus for playing back data from a recording mediumhaving recorded thereon a file system representing association betweenidentification information for identifying a file and a position wherethe file is recorded, a plurality of pieces of segment data (e.g., AVdata #n of annuli #n) constituting the file, and markers (e.g., salvagemarkers) for the respective pieces of segment data, each marker that isrecorded after a key marker specified in certain cases includinglocation information (e.g., a key-salvage-marker pointer) of the keymarker, the playback apparatus including detecting means (e.g., asalvage-marker detector 133, shown in FIG. 7) for detecting a lastmarker (e.g., a last salvage marker SM#10, shown in FIG. 28) in arecording area where data has been recorded on the recording medium buthas not been reflected on the file system, the last marker being amarker that is recorded at an end of the recording medium in a recordingprocess; and restoration processing means (e.g., a salvage processor134, shown in FIG. 7) for executing, for each of the pieces of segmentdata constituting the file, a restoration process of reflecting on thefile system segment data that has been recorded on the recording mediumbut has not been reflected on the file system, based on the locationinformation of the key marker (e.g., pointers to key salvage markersKSM#4, KSM#7, and KSM#10, shown in FIG. 29) and the location informationof segment data (e.g., location information of annuli #6 to #8, shown inFIG. 29), these pieces of location information being included in thelast marker detected by the detecting means.

In the playback apparatus according to the embodiment of the presentinvention, the key marker is specified, for example, when the size of amarker has reached a predetermined upper limit.

In the playback apparatus according to the embodiment of the presentinvention, the restoration processing means may read a marker specifiedas the key marker (e.g., salvage markers SM#4, SM#7, and SM#10, shown inFIG. 29) from the recording medium based on the location information ofthe key marker on the recording medium, and execute the restorationprocess based on the location information of the segment data, includedin the marker read (e.g., location information of annuli #1 and #2,included in the salvage marker SM#4, location information of annuli #3to #5, included in the salvage marker SM#7, and location information ofannuli #6 to #8, included in the salvage marker SM#10, shown in FIG.29), and based on the location information of the segment data, includedin the last marker (e.g., location information of the annuli #6 to #8,included in the last salvage marker SM#10, shown in FIG. 29).

In the playback apparatus according to the embodiment of the presentinvention, the detecting means may detect the last marker by executingbinary search (e.g., a process shown in FIG. 27) in the recording areawhere data has been recorded on the recording medium but has not beenreflected on the file system.

In the playback apparatus according to the embodiment of the presentinvention, each of the markers may include a first number of times(e.g., the number of times of circulating recording, shown in FIG. 8)representing the number of times of rewriting in a recording area wherethe marker is recorded on the recording medium, and when a marker isdetected in the recording area where data has been recorded on therecording medium but has not been reflected on the file system, and thedetecting means may determine whether the marker is the last markerbased on the first number of times included in the marker and a secondnumber of times representing the number of times of rewriting in therecording area where the marker is recorded on the recording medium, thesecond number of times having been reflected on the file system (e.g.,steps S204 and S208, shown in FIG. 27).

In the playback apparatus according to the embodiment of the presentinvention, each of the markers may include first date and timeinformation (e.g., a recording date and time, shown in FIG. 8)corresponding to a date and time of recording of the marker on therecording medium, and when a marker is detected in the recording areawhere data has been recorded on the recording medium but has not beenreflected on the file system, the detecting means may determine whetherthe marker is the last marker based on the first date and timeinformation included in the marker and second date and time informationcorresponding to a date and time of updating of the file system (e.g.,steps S204 and S208, shown in FIG. 27).

In the playback apparatus according to the embodiment of the presentinvention, each of the markers may include location information of theassociated segment data recorded on the recording medium (e.g., thelocation information of the annuli #6 to #8, included in the salvagemarker SM#10, shown in FIG. 29).

A playback method according to another embodiment of the presentinvention is a playback method for playing back data from a recordingmedium having recorded thereon a file system representing associationbetween identification information for identifying a file and a positionwhere the file is recorded, a plurality of pieces of segment data (e.g.,AV data #n of annuli #n) constituting the file, and markers (e.g.,salvage markers) for the respective pieces of segment data, each markerthat is recorded after a key marker specified in certain cases includinglocation information of the key marker (e.g., a key-salvage-markerpointer), the playback method including the steps of detecting a lastmarker (e.g., a last salvage marker SM#10, shown in FIG. 28) in arecording area where data has been recorded on the recording medium buthas not been reflected on the file system, the last marker being amarker that is recorded at an end of the recording medium in a recordingprocess (e.g., step S181, shown in FIG. 26); and executing, for each ofthe pieces of segment data constituting the file, a restoration processof reflecting on the file system segment data that has been recorded onthe recording medium but has not been reflected on the file system,based on the location information of the key marker (e.g., pointers tokey salvage markers KSM#4, KSM#7, and KSM#10, shown in FIG. 29) and thelocation information of segment data (e.g., location information ofannuli #6 to #8, shown in FIG. 29), these pieces of location informationbeing included in the last marker detected (e.g., step S186, shown inFIG. 26).

A program according to an embodiment of the present invention is aprogram for allowing a computer to execute a process of playing backdata from a recording medium having recorded thereon a file systemrepresenting association between identification information foridentifying a file and a position where the file is recorded, aplurality of pieces of segment data constituting the file, and markersfor the respective pieces of segment data, each marker that is recordedafter a key marker specified in certain cases including locationinformation of the key marker, the process including the steps ofdetecting a last marker (e.g., a last salvage marker SM#10, shown inFIG. 28) in a recording area where data has been recorded on therecording medium but has not been reflected on the file system, the lastmarker being a marker that is recorded at an end of the recording mediumin a recording process (e.g., step S181, shown in FIG. 26); andexecuting, for each of the pieces of segment data constituting the file,a restoration process of reflecting on the file system segment data thathas been recorded on the recording medium but has not been reflected onthe file system, based on the location information of the key marker(e.g., pointers to key salvage markers KSM#4, KSM#7, and KSM#10, shownin FIG. 29) and the location information of segment data (e.g., locationinformation of annuli #6 to #8, shown in FIG. 29), these pieces oflocation information being included in the last marker detected (e.g.,step S186, shown in FIG. 26).

A playback apparatus according to an embodiment of the present inventionis a playback apparatus for playing back data from a recording mediumhaving recorded thereon a file system representing association betweenidentification information for identifying a file and a recordingposition of the file on the recording medium, a plurality of pieces ofsegment data (e.g., AV data #n of annuli #n) constituting the file, andmarkers (e.g., salvage markers) for the respective pieces of segmentdata, each of the markers at least including location information of theassociated segment data recorded on the recording medium, each of themarkers being specified as a key marker when the size of the marker hasreached a predetermined upper limit, and each marker that is recordedafter the marker specified as the key marker further including locationinformation of the key marker on the recording medium (e.g., akey-salvage-marker pointer), the playback apparatus including detectingmeans (e.g., a salvage-marker detector 133, shown in FIG. 7) fordetecting a last marker (e.g., a last salvage marker SM#10, shown inFIG. 28) in a recording area where data has been recorded on therecording medium but has not been reflected on the file system, the lastmarker being a marker recorded last on the recording medium in arecording process; storage means (e.g., a volatile memory 121, shown inFIG. 7) for storing the location information of the key marker on therecording medium (e.g., pointers to key salvage markers KSM#4, KSM#7,and KSM#10, shown in FIG. 29) and the location information of segmentdata recorded on the recording medium (e.g., location information ofannuli #6 to #8, shown in FIG. 29), these pieces of location informationbeing included in the last marker detected by the detecting means; andsalvage means (e.g., a salvage processor 134, shown in FIG. 7) forexecuting, for each of the pieces of segment data constituting the file,a salvage process of reflecting on the file system segment data that hasbeen recorded on the recording medium but has not been reflected on thefile system, based on the location information of the key marker on therecording medium and the location information of the segment datarecorded on the recording medium, these pieces of location informationhaving been stored in the storage means.

Now, embodiments of the present invention will be described. A recordingand playback apparatus records on an optical disc audio data and videodata that are managed as files based on a predetermined file system(e.g., UDF (Universal Disc Format)), and records information referred toas salvage markers between pieces of the data recorded. When powersupply was interrupted and a recording process was not completednormally, for example, due to detachment of the battery, i.e., when datarecorded on the optical disc was not registered as a file in the filesystem, after the electric power is recovered, the recording position ofthe data that had been recorded on the optical disc before theinterruption of the recording process is identified with reference tothe salvage markers, and a file including the data that had beenrecorded before the interruption of the recording process is registeredin the file system based on the recording position. Thus, even when therecording process was not completed normally, it is possible to playback the data that had been recorded on the optical disc before theinterruption of the recording process. The series of processes describedabove will hereinafter be referred to as a salvage.

In order to check whether a file system has been recorded normally on anoptical disc, for example, when UDF (Universal Disc Format) is employedas the file system, an LVID (logical volume integrity descriptor) of UDFrecorded on the optical disc is referred to. The LVID is a flagindicating whether a file recorded on the optical disc has been closednormally. When the file has been closed normally and the file system hasbeen recorded normally, a close flag is set to the LVID. On the otherhand, when the file has not been closed normally and the file system hasnot been recorded normally, an open flag is set to the LVID.

FIG. 1 shows an example of area segmentation of an optical disc on whichaudio data and video data is recorded by a recording and playbackapparatus according to an embodiment of the present invention.

In the example shown in FIG. 1, an inner-side FS recording area 1, afile recording area 2, and an outer-side FS recording area 3 areprovided on the optical disc, in that order from the inner side.

In the inner-side FS recording area 1, management informationrepresenting what files are recorded on which parts of the filerecording area 2 is recorded. The management information is referred towhen a file is read from the optical disc. The management information issometimes referred to as a file system (FS). The management informationis updated when a file is recorded in the file recording area 2, a filerecorded in the file recording area 2 is updated, or a file recorded inthe file recording area 2 is deleted.

The file recording area 2 is divided into a non-real-time (NRT) area 11and a real-time (RT) area 12.

In the non-real-time area 11, data of files that do not requirereal-time property at the time of playback, such as index files, discinformation files, clip information files, and non-real-time metadatafiles (described later with reference to FIGS. 3 and 4), is recorded.

In the real-time area 12, data of files that require real-time property,such as audio data constituting audio files and video data constitutingvideo files, is recorded.

In the outer-side FS recording area 3, management information that isthe same as the management information recorded in the inner-side FSrecording area 1 is recorded. By recording the same managementinformation in the inner-side FS recording area 1 and the outer-side FSrecording area 3, even if it is not possible to read managementinformation recorded in one of the inner-side FS recording area 1 andthe outer-side FS recording area 3 due to a scar, dirt, or the like onthe optical disc, the possibility remains that the managementinformation in the other can be read. This serves to avoid situationswhere it is not possible to read various files recorded in the filerecording area 2.

Next, an overview of how audio data and video data are recorded in thereal-time area 12 of the optical disc will be described with referenceto FIGS. 2A to 2C.

In FIG. 2A, pieces of video data V and pieces of audio data Aaccompanying the pieces video data V are alternately arranged on aframe-by-frame basis. Hereinafter, this type of recording will bereferred to as frame-based interleaved recording.

In FIG. 2B, the entire series of video data and the entire series ofaudio data are arranged separately each as a single file. Hereinafter,this type of recording will be referred to as non-interleaved recording.

In FIG. 2C, pieces of video data V that are each longer than one framebut do not cover the entire series of video data and pieces of audiodata A that are each longer than one frame but do not cover the entireseries of audio data are alternately arranged.

When pieces of video data V and audio data A that are each longer thanone frame but do not cover the entire series of data are alternatelyrecorded from the inner side to the outer side of the optical disc (orvice versa), if different shades, different colors, or the like wereassigned to parts where pieces of video data V are recorded and partswhere pieces of audio data A are recorded, the parts where pieces ofvideo data V are recorded and the parts where pieces of audio data A arerecorded look like annuli that are formed on a cross section of a treetrunk.

Hereinafter, pieces of video data V and audio data A or the like thatare each longer than one frame but do not cover the entire series ofdata will be referred to as annulus data. In FIG. 2C, parts of a datasequence of video data V and parts of a data sequence of audio data Aare arranged periodically on an annulus-data basis. Hereinafter, thistype of recording, in which parts of a plurality of data sequences isarranged periodically on an annulus-data basis, will be referred to asannulus-based interleaved recording.

In the case of frame-based interleaved recording shown in FIG. 2A, videodata V and accompanying audio data A are written to the optical discalternately on a frame-by-frame basis. This type of recording is allowedwith a buffer that is capable of buffering video data V or audio data Aof at least one frame. Since the buffer suffices to store video data Vor audio data A of one frame, delay due to the buffering of video data Vor audio data A (recording delay) is small.

In the case of frame-based interleaved recording, however, since videodata V and audio data A are recorded on the optical disc alternately ona frame-by-frame basis, even when either video data or audio is edited,i.e., even when AV (audio-video) split editing is performed, both thevideo data V and the audio data A are read. This inhibits efficientreading of data from the optical disc.

For example, when only video data is edited, it suffices to read onlyvideo data V. When only video data V is read from an optical disc onwhich data has been recorded by frame-based interleaved recording, videodata V of one frame is read, and seeking to the recording position ofvideo data V of a next one frame is performed, and the video data V ofthe next frame is read. This operation is repeated. However, in the caseof frame-based interleaved recording, what is recorded between therecording position of video data V of a frame and the recording positionof video data V of a next frame is audio data A of one frame, whoseamount is small. Usually, the time for reading the small audio data A isshorter than the time for performing seeking to skip the audio data A.Thus, the overall reading time is shorter when both the video data V andthe audio data A are read than when only the video data V is read.However, it is not efficient to read the audio data A as well, whichwill not be edited.

In the case of non-interleaved recording shown in FIG. 2B, the entiresequence of video data and the entire sequence of audio data areseparately arranged and recorded on the optical disc. Thus, when AVsplit editing is performed, it is possible to read only video data V oraudio data A that is to be edited.

In the case of non-interleaved recording, the entire sequence of videodata and the entire sequence of audio data are separately arranged andrecorded on the optical disc; for example, the recording area of theoptical disc is divided into a video area and an audio area, and videodata is recorded in the video area and audio data is recorded in theaudio area. Thus, when data is written to the optical disc from theinner side to the outer side continuously, a buffer having such anenormous size sufficient to store the entire sequence of video data orthe entire sequence of audio data is used. With such a buffer of anenormous size, recording delay due to the buffering of video data oraudio data is quite long.

In view of the above, in one type of non-interleaved recording, thewriting of video data to the video area and the writing of audio data tothe audio data are performed alternately by time division.

In this case, however, seeking that moves a pickup (not shown) of a discdrive (not shown) from the video area to the audio area of the opticaldisc and vice versa frequently occurs. This considerably reduces theeffective recording rate. Furthermore, when the recording and playbackapparatus is a digital video camera, occurrence of seeking should beminimized from the viewpoint of mechanical impact.

In the case of annulus-based interleaved recording shown in FIG. 2C,pieces of video data and audio data are alternately arranged andrecorded on an annulus-data basis. The size of annulus data is longerthan one frame but do not cover the entire sequence of data. Inpractice, however, it is desired that the following first and secondconditions be further satisfied.

The first condition is that the seek time for performing seeking to skipa recording area of annulus data is shorter than the time for readingthe annulus data from the optical disc. That is, since it does notdiffer from the framed-based interleaved recording (FIG. 2A) when it isquicker to read annulus data than to skip the annulus data, the firstcondition is that it is quicker to skip annulus data than to read theannulus data. Preferably, the seek time is sufficiently shorter than theread time.

The second condition is that the size of annulus data is such that abuffer of a practical size that allows buffering the annulus dataexists. That is, in the case of annulus-based interleaved recording,since pieces of video data V and audio data A are alternately arrangedand recorded on an annulus-data basis, a buffer for buffering at leastvideo data V or audio data A on an annulus-data basis is used to recordthe pieces of video data V and the pieces of audio data A. Thus, withouta buffer that is capable of buffering video data V or audio data A on anannulus-data basis, it is not possible to record data by theannulus-based interleaved recording. Thus, the second condition is theexistence of a buffer of a practical size that allows buffering annulusdata.

While annulus data is buffered in a buffer, it is not possible to recordthe annulus data on the optical disc, so that a recording delay occursdue to the buffering of the annulus data in the buffer. The delay timecorresponds to the size of the annulus data buffered in the buffer,i.e., the size of the buffer. Thus, for example, when the delay time dueto the buffering of the annulus data in the buffer is restricted bysystem design, the delay time due to the buffering of the annulus datashould be within the restricted time.

According to the first condition, the size of annulus data should bemaximized. On the other hand, according to the second condition, thesize of annulus data should be minimized. Thus, the two conditionsconflict with each other.

In order to satisfy the first condition that the seek time forperforming seeking to skip annulus data is shorter than the read timefor reading the annulus data, usually, annulus data must be located in aplurality of tracks of the optical disc, i.e., the size of annulus datamust be larger than one track of the optical disc. In order that theseek time for annulus data be sufficiently shorter than the read timefor the annulus data, usually, the size of annulus data shouldcorrespond approximately to some tracks of the optical disc. The size ofone track is on the order of several hundred kilobytes (KB), although itdepends on the radial position of the track.

As for the second condition that a buffer of a practical size thatallows buffering annulus data exists, the upper limit of the practicalsize of the buffer is currently on the order of several ten megabytes(MB).

Thus, the size of annulus data should be in a range of roughly severalMB to several ten MB. This size roughly corresponds to several tentracks of the optical disc. As described earlier, since video data V andaudio data A alternately arranged and recorded on the optical disc byunits of this size look like annuli of a tree trunk, data of this sizewill be referred to as annulus data. The annulus data may include dataother than AV data.

Next, the relationship between annulus data and salvage markers will bedescribed with reference to FIGS. 3 and 4.

FIG. 3 shows an example order of recording data. In FIG. 3, “SM#1”,“SM#2”, and “SM#3” denote salvage markers. “A#1”, “A#2”, and “A#3”denote audio data. “V#1” and “V#2” denote video data. #1, #2, and soforth are numerals for identifying annuli.

In FIG. 3, a salvage marker SM#1, audio data A#1, video data V#1, asalvage marker SM#2, audio data A#2, video data V#2, a salvage markerSM#3, and audio data A#3 are recorded, in that order from the left. Thatis, one salvage marker is recorded in association with each piece ofannulus data.

A salvage marker includes a recognition pattern representing that thedata is a salvage marker (this recognition pattern will hereinafter bereferred to as a salvage ID), and identification information foridentifying a file to which the data belongs (e.g., a file name). Therecording and playback apparatus can detect the salvage marker bysearching for the salvage ID in data read from the real-time area 12.Information included in the salvage marker will be described later indetail with reference to FIG. 8.

Upon detecting loading of an optical disc on which a recording processwas interrupted in the middle without completion, the recording andplayback apparatus searches for a salvage ID on the optical disc. Forexample, when the salvage ID included in the salvage marker SM#1 isdetected, the recording and playback apparatus reads the salvage markerSM#1 recorded at the position of the salvage ID. Then, based on theidentification information for identifying a file (e.g., a file name X),included in the salvage marker SM#1, the recording and playbackapparatus determines that the audio data A#1 and the video data V#1,recorded subsequently to the salvage marker SM#1, are data constitutingthe file X.

Then, searching for a salvage ID is continued. When the salvage IDincluded in the salvage marker SM#2 is detected, based on theidentification information for identifying a file (e.g., also the filename X), included in the salvage marker SM#2, the recording and playbackapparatus determines that the audio data A#2 and the video data V#2,recorded subsequently to the salvage marker SM#2, are data constitutingthe file X.

Similarly, further salvage markers are read and data included in thefile X is identified. By sequentially tracking salvage markers in themanner described above, audio data and video data that have beenrecorded but not yet reflected on the file system as files are searchedfor, and the file X including the audio data and video data found by thesearching is registered in the file system as a single file.

FIG. 4 shows the state of recording position at the time when arecording process was interrupted. Also in FIG. 4, a salvage markerSM#3, audio data A#3, video data V#3, a salvage marker SM#4, and audiodata A#4 are recorded, in that order from the left similarly to FIG. 3.At the position indicated by an arrow as “recording interruption point”in the middle of video data V#4 on the right, recording of the videodata V#4 was interrupted. Obviously, a salvage marker SM#5 that is to berecorded subsequently is not recorded on the recording medium.

In the vicinity of the recording interruption point, the audio data A#3and the video data V#3 recorded between the salvage markers SM#3 andSM#4 can be used as parts of data contained in the file. However, datasubsequent to the salvage marker SM#4 will not be used. Thus, a singlefile is created using data before the salvage marker SM#4.

Alternatively, the audio data A#4 and the fragment of the video data V#5subsequent to the salvage marker SM#4 may be used. In this case,however, when a salvaged file is played back, video could be disruptedor missing in the vicinity of the end of the file. In that case, byediting the data by cutting the data at a point immediately before thedata becomes disrupted or missing, a file including all the datarecorded before the recording interruption point can be created.

Although audio data and video data are included in the same file in theexamples shown in FIGS. 3 and 4, audio data and video data may beincluded in separate files. In that case, audio data and video datadetected by tracking salvage markers after the recording was interruptedas shown in FIG. 4 are registered as separate files in the file system.In the following description, it is assumed that audio data and videodata are managed as separate files.

FIGS. 3 and 4 show directory structures that are employed when datarecorded on the file recording area 2 of the optical disc are managed asfiles.

As shown in FIG. 5, a PROAV directory 32 is provided immediately under aroot directory (ROOT) 31. Under the PROAV directory 32, video data,audio data, edited video data and audio data, and other data are storeddirectly or in subdirectories.

In the PROAV directory 32, a disc metafile (DISCMETA.XML) 41, which is afile including titles and comments for all the data recorded on theoptical disc, an index file (INDEX.XML) 42 including managementinformation and the like for managing all the clips and editing listsrecorded on the optical disc, and index file (INDEX.BUP) 43, which is acopy of the index file 42, are provided. Reliability is enhanced byproviding two files of the same content.

Furthermore, under the PROAV directory 32, a disc information file(DISCINFO.XML) 44 and a disc information file (DISCINFO.BUP) 45 areprovided. The disc information file 44 includes metadata relating to theentire data recorded on the optical disc, such as disc property,playback start position, and information indicating prohibition ofrecording on the disc. The disc information file 45 is a copy of thedisc information file 44. Reliability is enhanced by providing two filesof the same content.

Furthermore, under the PROAV directory 32, a clip root directory (CLPR)33 where clip data is provided in subdirectories, and an edit list rootdirectory (EDTR) 34 where data of edit lists are provided insubdirectories, are provided.

In the clip root directory 33, data of clips recorded on the opticaldisc is managed in separate directories for the respective clips. In theexample shown in FIG. 5, three clips of data are managed separately in aclip directory (C0001) 51, a clip directory (C0002) 52, and a clipdirectory (C0003) 53, respectively.

A clip is a unit of the number of times of an imaging process executed.Also, a clip serves as a unit of time taken from the start to the end ofthe imaging process, a unit of the length of various types of dataobtained through the imaging process, or a unit of the data volume ofvarious types of data obtained through the imaging process. Furthermore,a clip sometimes refers to a piece of the various types of data.

In the edit list root directory 34, edit lists (editing informationindicating how clips have been edited in editing processes) recorded onthe optical disc are managed in separate directories for respectiveediting processes. In the example shown in FIG. 5, four edit lists aremanaged in an edit list directory (E0001) 61, an edit list directory(E0002) 62, an edit list directory (E0003) 63, and an edit listdirectory (E0004) 64, respectively.

In subdirectories of the clip directory 51 under the clip root directory33, the data of clips recorded on the optical disc are managed as filesas shown in FIG. 6.

In the example shown in FIG. 6, the clip directory 51 includes a clipinformation file (C0001C01.SMI) 81 for managing this clip, a video datafile (C0001V01.MXF) 82 composed of video data of this clip, eight audiodata files (C0001A01.MXF to C0001A08.MXF) 83 to 90 composed of audiodata of the respective channels of this clip, a low-resolution data file(C0001S01.MXF) 91 composed of low-resolution data corresponding to thevideo data of this clip (video data composed of the same material as thevideo data, and having a lower resolution and a smaller data volume thanthe video data), and a non-real-time metadata file (C0001M01.XML) 92composed of clip metadata not requiring real-time property, such as aconversion table for associating a linear time code (LTC) of essencedata of this clip with a frame number.

The clip directory 51 also includes a frame metadata file (C0001R01.BIM)93 composed of frame metadata requiring real-time property, such as anLTC for essence data of this clip, and a picture pointer file(C0001I01.PPF) 94 describing a frame structure of the video data file 82(e.g., information regarding compression method of each picture in MPEG,and information such as an offset address from the head of the file).

Of the files shown in FIGS. 5 and 6, data of files not requiringreal-time property, such as the disc metafile 41, the index files 42 and43, the disc information files 44 and 45 in the PROAV directory 32, andthe clip information file 81 and the non-real-time metadata file 92 inthe clip directory 51, is recorded in the non-real-time area 11 of theoptical disc.

Data of files requiring real-time property, such as the video data file82, the audio data files 83 to 90, the frame metadata file 93, and thepicture pointer file 94 in the clip directory 51, is recorded in thereal-time area 12 of the optical disc.

FIG. 7 shows the construction of a recording and playback apparatusaccording to an embodiment of the present invention. In a recording andplayback apparatus 110, a spindle motor 112 drives an optical disc 111based on a spindle-motor driving signal fed from a servo controller 115,for example, at a constant linear velocity (CLV) or a constant angularvelocity (CAV).

During recording, a pickup 113 controls output of laser light based on arecording signal fed from a signal processor 116, thereby recording therecording signal on the optical disc 111. During playback, the pickup113 irradiates the optical disc 111 with laser light, converts laserlight reflected from the optical disc 111 into a current signal, andsupplies the current signal to a radio-frequency (RF) amplifier 114. Thepoint irradiated with laser light is controlled according to a servosignal fed from the servo controller 115 to the pickup 113.

The RF amplifier 114 generates a focus error signal, a tracking errorsignal, and a playback signal based on the current signal fed from thepickup 113. The RF amplifier 114 supplies the tracking error signal andthe focus error signal to the servo controller 115, and supplies theplayback signal to the signal processor 116.

The servo controller 115 performs a focus servo operation and a trackingservo operation. More specifically, the servo controller 115 generates afocus servo signal and a tracking servo signal based on the focus errorsignal and the tracking error signal, respectively, and supplies thefocus servo signal and the tracking servo signal to an actuator (notshown) of the pickup 113. Also, the servo controller 115 generates aspindle-motor driving signal for driving the spindle motor 112, therebyperforming a spindle servo operation to control the speed of rotation ofthe optical disc 111 as desired.

The servo controller 115 also performs a sled control to move the pickup113 in the radial direction of the optical disc 111 and thereby changethe position of irradiation with laser light. The position for reading asignal from the optical disc 111 is set by a controller 120, and theposition of the pickup 113 is controlled so that a signal is read fromthe signal reading position that has been set.

The signal processor 116 modulates audio data, video data, other data,and salvage markers to be recorded on the optical disc 111, input from amemory controller 117, thereby generating recording signals, andsupplies the recording signals to the pickup 113. Also, the signalprocessor 116 demodulates playback signals input from the RF amplifier114, thereby generating playback data. The playback data is fed to thememory controller 117.

The memory controller 117 causes the audio data, video data, and otherdata to be recorded on the optical disc 111, input from the dataconverter 119, and salvage markers generated by a salvage-markergenerator 132, to be buffered in a memory 118, and reads these items andsupplies the items to the signal processor 116 as needed. Also, thememory controller 117, as needed, extracts audio data, video data, andother data included in playback data fed from signal processor 116 andbuffers these items in the memory 118, and reads these items and supplythem to a data converter 119. Also, the memory controller 117 extractssalvage markers included in the playback data fed from the signalprocessor 116, and, as needed, stores the salvage markers in the memory118, reads the salvage markers, and supplies the salvage markers to thecontroller 120.

The data converter 119 encodes, for example, video signals and audiosignals acquired by a video camera (not shown), or video signals andaudio signal played back from an arbitrary recording medium (not shown),according to the Moving Picture Experts Group (MPEG) standard, the JointPhotographic Experts Group (JPEG) standard, or the like, and suppliesthe resulting audio data and video data to the memory controller 117.The data converter 119 may be omitted.

The data converter 119 decodes audio data and video data included in theplayback data fed from the memory controller 117, converts the resultingvideo signals and audio signals into output signals in a predeterminedformat, and outputs the resulting signals to a signal input/output unit141.

The controller 120 controls the servo controller 115, the signalprocessor 116, the memory controller 117, the data converter 119, and avolatile memory 121, thereby performing a recording process a playbackprocess, and so forth. Furthermore, the controller 120 generatesinformation that is to be held in a non-volatile memory 122.

The controller 120 includes an allocation manager 131, a salvage-markergenerator 132, a salvage marker detector 133, and a salvage processor134.

The allocation manager 131 manages a recording position, a playbackposition, and so forth of data on the optical disc 111.

The salvage-marker generator 132 generates salvage markers. For example,the salvage marker 132 generates a salvage marker #n, which will bedescribed later with reference to FIG. 8. The salvage-marker generator132 supplies salvage markers generated to the memory controller 117.Furthermore, the salvage-marker generator 132 is capable of storingsalvage markers generated in an internal memory.

The salvage-marker detector 133 detects a last salvage marker, which isa marker that has been recorded last in a recording process. Morespecifically, of a plurality of salvage markers recorded on the opticaldisc 111, the salvage-marker detector 133 detects a last salvage marker,i.e., a marker that is recorded last on the optical disc 111 in arecording process in a recording area that has not yet been reflected onthe file system. That is, a last salvage marker is a latest salvagemarker that was recorded at a time closest to the current time in arecording area that has been recorded on the optical disc 111 but hasnot yet been reflected on the file system.

The salvage processor 134 performs a salvage process. More specifically,the salvage processor 134, based on salvage markers, performs a processfor reflecting on the file system audio data and video data that havebeen recorded on the optical disc 111 but have not been reflected on thefile system. That is, a salvage process is a process for reflecting onthe file system audio data and video data that have been recorded on theoptical disc 111 but have not been reflected on the file system. Also,the salvage processor 134 stores data used in the salvage process in avolatile memory 121 as needed.

A non-volatile memory 122 stores non-volatile-memory informationgenerated by the controller 120.

The salvage-marker generator 132, the salvage-marker detector 133, andthe salvage processor 134 may be provided externally to the controller120 (e.g., so as to be connected to the signal processor 116 and thememory controller 117).

Furthermore, although not shown, the recording and playback apparatus110 may include a disc loading/unloading motor for loading and unloadingthe optical disc 111, a display for displaying operation status of therecording and playback apparatus 110 and various guidance information,and an operation unit for accepting input of operations by a user.

Next, information included in a salvage marker will be described withreference to FIG. 8. FIG. 8 shows an example of information that isincluded in a salvage marker SM#n associated with an annulus #n. Thesalvage marker SM#n is generated, for example, by the salvage-markergenerator 132 shown in FIG. 7.

The information included in a salvage marker is divided into managementdata and stored data. The management data includes a salvage marker ID,an increment number, a recording date and time, the number of times ofcirculating recording, key-salvage-marker pointers, a unique material ID(UMID), and stored-data header.

The salvage marker ID serves to identify the data as a salvage markerand is used to detect the salvage marker. The increment number serves torepresent continuity with other salvage markers across audio data andvideo data, such as a serial number. The increment number of the salvagemarker shown in FIG. 8 will be denoted as #n.

The recording date and time represents the date and time when thesalvage marker was recorded. The recording date and time serves toexclude data that has been deleted intentionally by the user from fullsalvage. Furthermore, for example, the recording date and time may beused for the salvage-marker detector 133 to detect a last salvagemarker. Instead of the recording date and time, either the date and thetime, or other data that allows identifying the timing of recording maybe used.

The number of times of circulating recording is the number of times ofrewriting at the position where the salvage marker is recorded on theoptical disc 111. In the recording on the optical disc 111, circulatingrecording is performed so that the number of times of writing becomesuniformed over the recording area of the optical disc 111. In thesalvage marker, the number of times of recording at the recording areawhere the salvage marker (associated annulus data) is recorded isincluded. Furthermore, in the file system, the number of times ofwriting to the recording area of the optical disc 111 is managed. Thatis, the management information of the file system includes the number oftimes of circulating recording in the recording area of the optical disc111. The number of times of circulating recording is used, for example,for the salvage-marker detector 133 to detect a last salvage marker.That is, for example, the salvage-marker detector 133 detects a lastsalvage marker using the number of times of circulating recording.Without limitation to the number of times of circulating recording,simply, the number of times of recording in a certain recording area ofthe optical disc 111 may be used.

The key-salvage-marker pointer is location information (record)representing the position where a key salvage marker (described later indetail) that has been recorded on the optical disc 111 is recorded. Itis possible to store a predetermined number (e.g., 100) of key-salvagemarker pointers.

The UMID serves to uniquely identify audio data and video data of anassociated annulus #n. The stored-data header indicates that subsequentdata is stored data of the salvage marker.

The stored data of the salvage marker is divided into file data andfile-system management data. The file data includes program metadata,added part of index file, clip information, and non-real-time metadatathat are non-real-time files associated with audio data and video dataof annuli #(n+1), #(n+2), . . . subsequent to the annulus #n associatedwith the salvage marker SM#n. Also for data other than the index file,only added part may be recorded in the stored data.

The stored data of the salvage marker corresponds to the programmetadata file 41, the index file 42, the clip information 81, and thenon-real-time metadata 92 described with reference to FIGS. 5 and 6.

The file-system management data includes a file entry, annulus locationinformation, and a defect list.

The file entry serves to identify a file that is restored based on thesalvage marker, such as a file name. The annulus location informationrepresents the position where audio data and video data of annuli#(n−2), #(n−3) . . . up to two annuli before the annulus #n associatedwith the salvage marker SM#n. The defect list represents positions wheredefects have occurred during the recording of annulus data.

As long as the upper limit of size defined for the salvage marker (e.g.,64 kilobytes), it is possible to store the location information of theannulus data #(n−2) two annuli before in the location information ofannulus data recorded in the salvage marker SM#(n−1) one annulus before.However, if the overall size of the salvage marker exceeds the upperlimit when the location information of the annulus data #(n−2) twoannuli before is stored, only the annulus data #(n−2) two annuli beforeis stored.

A salvage marker in which maximum location information of annulus dataup to two annuli before is stored so that the overall size of thesalvage marker does not exceed the upper limit is specified as a keysalvage marker. Each salvage marker recorded after the key salvagemarker includes a key-salvage-marker pointer corresponding to locationinformation of the key salvage marker on the optical disc 111.

Next, non-volatile-memory information stored in the non-volatile memory122 will be described with reference to FIG. 9. FIG. 9 shows an exampleof information included in non-volatile-memory information.

The non-volatile-memory information is divided into management data andstored data. The management data includes an update date and time, anindex ID, and a stored-data header.

The update date and time indicates the latest date and time when thenon-volatile-memory information was recorded or updated. The index ID isspecific information that serves to uniquely identify the optical disc111 loaded on the recording and playback apparatus 110 when thenon-volatile-memory information was recorded. For example, informationthat is assigned when the non-real-time area 11 is formatted is used.The stored-data header indicates that subsequent data is stored data ofthe non-volatile-memory information.

The stored data of the non-volatile-memory information includes acurrent-salvage-marker pointer, key-salvage-marker pointers, annuluslocation information not yet recorded in salvage markers on the disc,and recorded annulus information.

The current-salvage-marker pointer indicates the position where thelatest one of the salvage markers that have been recorded on the opticaldisc 111 is recorded. Each of the key-salvage-marker pointers representsthe recording position of a key salvage marker that has been recorded onthe optical disc 111. It is possible to store a predetermined number(e.g., 100) of key-salvage-marker pointers. The annulus locationinformation not yet recorded in salvage marker on the disc includesannulus location information that have not yet been recorded on theoptical disc 111 as included in salvage markers. The recorded annulusinformation serves to identify the latest annulus data that has beenrecorded on the optical disc 111.

Next, a process for recording audio data and video data on the opticaldisc 111 by the recording and playback apparatus 110 (hereinafter simplyreferred to as a recording process) will be described with reference toa flowchart shown in FIG. 10. The recording process is started, forexample, when audio signals and video signals are fed from the signalinput/output unit 141 according to an instruction by the user.

In step S1, the data converter 119, under the control of the controller120, starts compressing the audio signals and video signals fed from thesignal input/output unit 141, and outputs the resulting audio data andvideo data to the memory controller 117. The memory controller 117,under the control of the controller 120, starts buffering the audio dataand video data input from the data converter 119 in the memory 118.

In step S2, the controller 120 initializes a parameter n that is used toidentify an annulus to 1. In step S3, the salvage-marker generator 132generates a salvage marker SM#n associated with the annulus #n. Forexample, when n is 1, the salvage-marker generator 132 generates asalvage marker SM#1 associated with the annulus #1. The process executedin step S3 will be described below with reference to FIG. 11.

In step S21, the salvage-marker generator 132 obtains a previouslygenerated salvage marker SM#(n−1) from an internal memory as a templateof salvage marker. The salvage-marker generator 132 subsequentlygenerates salvage markers SM#n by updating information included in thetemplate of salvage marker. When the previously generated salvage markerSM#(n−1) is absent, the salvage-marker generator 132 obtains a defaulttemplate stored in the internal memory instead of the salvage markerSM#(n−1).

Alternatively, without executing step S21, the template in the internalmemory of the salvage-marker generator 132 may be updated in step S22and subsequent steps.

In step S22, the salvage-marker generator 132 updates the recording dateand time of the template to the current time and date, and incrementsthe increment number by 1.

In step S23, the salvage-marker generator 132 records the number oftimes of circulating recording of the annulus #n. In the optical disc111 in this embodiment, the number of times of recording in anyrecording area is recorded. Thus, the salvage-marker generator 132increments by 1 the number of times of recording in a specific recordingarea, read from the optical disc 111 via some components (the pickup113, the RF amp 114, the signal processor 116, and so forth), andrecords the result as the number of times of circulating recording ofthe annulus #n.

In step S24, when the salvage marker SM#(n−1) was specified as a keysalvage marker in a previous iteration of the process for generating thesalvage marker SM#(n−1), the salvage-marker generator 132 obtains thelocation information (record) of the salvage marker SM#(n−1) from theallocation manager 131, and adds it to key salvage markers in thetemplate. That is, in salvage markers after a specified key salvagemarker, key-salvage-marker pointers are added (stored).

In step S25, the salvage-marker generator 132 obtains NRT metadataassociated with the audio data and video data of a next annulus #(n+1)(e.g., from the controller 120), and overwrites the file data of thetemplate with the NRT metadata.

In step S26, the salvage-marker generator 132 obtains from theallocation manager 131 the location information (record) of the audiodata and the video data of the annulus #(n−2) two annuli before.

In step S27, the salvage-marker generator 132 determines whether thesize of the salvage marker being generated exceeds a predeterminedthreshold (e.g., an upper limit of 64 kilobytes) when the locationinformation (record) of the audio data and video data of the annulus#(n−2) obtained in step S26 is added to the location information of thetemplate.

When it is determined that the size of the salvage marker beinggenerated does not exceeds the predetermined threshold, the processproceeds to step S28. In step S28, the salvage-marker generator 132 addsthe location information (record) of the audio data and video data ofthe annulus #(n−2), obtained in step S26, to the annulus locationinformation of the template.

In step S29, the salvage-marker generator 132 determines whether thesize of the salvage marker SM#n being generated exceeds thepredetermined threshold when the location information (record) of theaudio data and video data of another annulus is added to the annuluslocation information of the template. When it is determined that thesize of the salvage marker SM#n being generated exceeds thepredetermined threshold when the location information (record) of theaudio data and video data of another annulus is added to the annuluslocation information of the template, the process proceeds to step S30.

In step S30, the salvage-marker generator 132 specifies the salvagemarker SM#n being generated as a key salvage marker, and updates otherinformation in the template as needed, thereby fully generating thesalvage marker SM#n, and outputs the salvage marker SM#n generated tothe memory controller 117. At this time, the salvage-marker generator132 adds the own location information of the salvage marker SM#n as akey salvage marker. Thus, a salvage marker specified as a key salvagemarker includes a key-salvage-marker pointer indicating its own locationinformation. Alternatively, a salvage marker specified as a key salvagemarker may be such that a key-salvage-marker pointer indicating its ownlocation information is not included.

The file entry of the template are maintained the same form the start tothe end of the recording process, and when the next recording process isstarted, a file entry different from that in the current iteration isgenerated. Thus, annuli constituting the same file are distinguishedfrom each other.

When it is determined that the size of the salvage marker SM#n beinggenerated exceeds the predetermined threshold even when the locationinformation (record) of the audio data and video data of another annulusis added to the annulus location information of the template, i.e., whenthe location information of audio data and video data of annuli up tothe annulus two annuli before is maximally stored, the salvage markerSM#n is specified as a key salvage marker. That is, when the data sizeof a salvage marker has reached a predetermined upper limit, the salvagemarker is specified as a key salvage marker.

When it is determined in step S29 that the size of the salvage markerSM#n being generated does not exceed the predetermined threshold evenwhen the location information (record) of the audio data and video dataof another annulus is added to the annulus location information of thetemplate, step S30 is skipped.

When it is determined in step S27 that the size of the salvage markerSM#n being generated exceeds the predetermined threshold, the processproceeds to step S32. In step S32, the salvage-marker generator 132deletes the location information (record) of the audio data and videodata of the annulus #(n−1) and previous annuli recorded in the template,and records (updates) only the location information (record) of theaudio data and video data of the annulus #(n−2), obtained in step S26,in the annulus location information of the template. The process thenproceeds to step S31.

When it is determined in step S29 that the size of the salvage markerSM#n being generated does not exceed the predetermined threshold evenwhen the location information (record) of the audio data and video dataof another annulus is added to the annulus location information of thetemplate, after step S30 or step S32, the process proceeds to step S31,in which the salvage-marker generator 132 updates other information asneeded. The process is then exited.

This concludes the description of the annulus-#n salvage-markergenerating process. Through the process shown in FIG. 11, the salvagemarker SM#n (FIG. 8) of the annulus #n can be generated. In the salvagemarker of the annulus #n, “the location information (record) of theaudio data and video data of the annulus #(n−2)”, which is the locationinformation of annulus data that is at least two annuli before, isrecorded. Furthermore, a salvage marker SM#n of an annulus #n thatstores maximum location information of annulus data up to annulus twoannuli before without its overall size not exceeding the upper limit isspecified as a key salvage marker. When the data size of a salvagemarker SM#n of an annulus #n has reached a predetermined upper limit,the salvage marker SM#n is specified as a key salvage marker, and thelocation information of the key salvage marker on the optical disc 111(a key-salvage-marker pointer) is stored in salvage markers that arerecorded after the key salvage marker. The salvage marker SM#n generatedis fed to the memory controller 117.

Referring back to FIG. 10, after the salvage marker SM#n is generated instep S3, in step S4, the memory controller 117 monitors the memory 118under the control of the controller 120 to determine whether audio dataand video data of one annulus have been buffered in the memory 118, andwaits until it is determined that audio data and video data of oneannulus have been buffered. When audio data and video data of oneannulus have been buffered, the process proceeds to step S5. Steps S3and S4 may be executed in parallel.

In step S5, the memory controller 117, under the control of thecontroller 120, supplies the salvage marker SM#n generated in step S3and fed from the salvage-marker generator 132, and the audio data andvideo data of the annulus #n, having been buffered in the memory 118, tothe signal processor 116. Hereinafter, the audio data and the video dataof the annulus #n will be referred to as audio data A#n and video dataV#n. Also, the audio data A#n and the video data V#n will becollectively denoted as AV data #n.

The signal processor 116 modulates the salvage marker SM#n, the audiodata A#n, and the video data V#n fed thereto into recording signals, inthat order, and supplies the recording signals to the pickup 113. Thepickup 113 records the recording signals input from the signal processor116 on the optical disc 111.

In step S6, the controller 120 updates the non-volatile-memoryinformation in the non-volatile memory 122. When the non-volatile-memoryinformation is absent in the non-volatile memory 122,non-volatile-memory information is newly generated similarly to theupdating of the non-volatile-memory information described below.

More specifically, the recording date and time of the management data ofthe non-volatile-memory information is updated to the current date andtime, and the current-salvage-marker pointer of the management data isupdated with the location information (record) of the salvage markerSM#n recorded on the optical disc 111 in step S5. Furthermore, when thesalvage marker SM#n generated in step S3 is specified as a key salvagemarker in step S30, the location information (record) of the salvagemarker SM#n as a key salvage marker is added to the key-salvage-markerpointers in the management data. Furthermore, the location information(record) of the AV data #n of the annulus #n and the locationinformation (record) of the AV data #(n−1) of the annulus #(n−1) arerecorded in “annulus location information not yet recorded in salvagemarkers on disc”. Thus, the non-volatile-memory information shown inFIG. 9 is updated. Although a single piece of “annulus locationinformation not yet recorded in salvage markers on disc” is included inthe example shown in FIG. 9, after step S6, two pieces of locationinformation, namely, the location information (record) of the AV data #nof the annulus #n and the location information (record) of the AV data#(n−1) of the annulus #(n−1), are recorded.

In step S7, the memory controller 117 checks whether audio data andvideo data that have not been output to the signal processor 116 arebuffered in the memory 118, and notifies the controller 120 of thechecking result. Based on the checking result fed from the memorycontroller 117, the controller 120 determines whether or not to exit therecording process. More specifically, when audio data and video datathat have not been output to the signal processor 116 are buffered inthe memory 118, it is determined that the recording process is not to beexited. Then, the process proceeds to step S8, in which the parameter nis incremented by 1. Then, the process returns to step S3, andsubsequent steps are repeated.

When it is determined in step S7 that audio data that have not beenoutput to the signal processor 116 are not buffered in the memory 118,it is determined that the recording process is to be exited. Then, theprocess proceeds to step S9.

In step S9, the controller 120 creates a file system (managementinformation) for managing, as a file, the salvage marker, audio data,and video data recording on the optical disc 111 in step S5, suppliesthe file system (management information) to the signal processor 116,updates the file system (management information) recorded in at leastone of the inner-side FS recording area 1 and the outer-side FSrecording area 3, and records information indicating that the filesystem has been normally closed. For example, when the file system isUDF, a close flag is set in a logical volume integrity descriptor (LVID)of UDF. Furthermore, the controller 120 deletes the non-volatile-memoryinformation in the non-volatile memory 122. This concludes descriptionof the recording process.

The above description applies to cases where the recording process wascompleted normally. This embodiment is directed to dealing with caseswhere the recording process was interrupted without normally completing.

Next, the recording process described above will be described in moredetail. FIGS. 12 to 20 show temporal changes in main parts ofnon-volatile-memory information stored in the non-volatile memory 122,recorded data that has been reflected on the file system (managementinformation), the status of recording of data in the real-time area 12of the optical disc 111, and main information included in salvagemarkers.

FIG. 12 shows the state before the recording process is started. In thisstate, no information is stored in the non-volatile memory 122. Datathat has already been recorded on the optical disc 111 exists, and thedata has already been reflected on the file system.

FIG. 13 shows the state where the salvage marker SM#1 and the AV data #1associated with the annulus #1 are going to be recorded on the opticaldisc 111.

FIG. 14 shows the state where the salvage marker SM#1 and part of the AVdata #1 associated with the annulus #1 have been recorded on the opticaldisc 111 and the salvage marker SM#2 and the AV data #2 associated withthe annulus #2 are going to be recorded on the optical disc 111.Immediately after the recording of the salvage marker SM#1 associatedwith the annulus #1, a current-salvage-marker pointer (hereinafter alsodenoted as CSM) representing the location information of the recordedsalvage marker SM#1 is recorded in the non-volatile-memory information(this corresponds to step S6 shown in FIG. 10). That is, of salvagemarkers that have been recorded on the optical disc 111, acurrent-salvage-marker pointer (CSM) representing the position of thelatest salvage marker is recorded in the non-volatile-memoryinformation.

FIG. 15 shows the state where the recording of the AV data #1 associatedwith the annuls #1 on the optical disc 111 has been completed, thesalvage marker SM#2 and part of the AV data #2 associated with theannulus #2 have been recorded on the optical disc 111, and the salvagemarker SM#3 and the AV data #3 associated with the annulus #3 are goingto be recorded on the optical disc 111. The salvage marker SM#3, whichhas not yet been recorded, includes the location information (record) ofthe annulus #1 that is two annuli before. Since the salvage marker SM#3including the location information (record) of the recorded annulus #1has not yet been recorded, the location information (record) of theannulus #1 that is two annuli before is recorded in thenon-volatile-memory information. Furthermore, the location informationof the salvage marker SM#2 is recorded as a CSM in thenon-volatile-memory information.

FIG. 16 shows the state where the recording of the AV data #2 associatedwith the annulus #2 on the optical disc 111 has been finished, thesalvage marker SM#3 and part of the AV data #3 associated with theannulus #3 have been recorded on the optical disc 111, and the salvagemarker SM#4 and part of the AV data #4 associated with the annulus #4are going to be recorded on the optical disc 111. The salvage markerSM#4, which has not yet been recorded, includes the location information(record) of the annulus #1 and the annulus #2, which are two or moreannuli before. Since the data size has become close to the upper limit,the salvage marker SM#4 is specified as a key salvage marker. Since thesalvage marker SM#4 including the location information (record) of therecorded annulus #2 has not yet been recorded, the location information(record) of the annulus #2 is recorded in the non-volatile-memoryinformation. At this time, the location information (record) of theannulus #1, which has been recorded in the non-volatile-memoryinformation as shown in FIG. 15, is deleted since the salvage markerSM#3 including its location information has been recorded (this appliessimilarly to the following description). Furthermore, the locationinformation of the salvage marker SM#3 is recorded as a CSM in thenon-volatile-memory information.

FIG. 17 shows the state where the recording of the AV data #3 associatedwith the annulus #3 on the optical disc 111 has been finished, thesalvage marker SM#4 and part of the AV data #4 associated with theannulus #4 have been recorded on the optical disc 111, and the salvagemarker SM#5 and part of the AV data #5 associated with the annulus #5are going to be recorded on the optical disc 111. Furthermore, it isassumed that the salvage marker SM#4 associated with the annulus #4 hasbeen specified as a key salvage marker. In the recorded salvage markerSM#4 specified as a key salvage marker, a key-salvage-marker pointerrepresenting the location information of the salvage marker SM#4 isrecorded. Hereinafter, a key salvage marker will also be denoted as aKSM, and a salvage marker SM#n specified as a key salvage marker willalso be denoted as KSM#n. Furthermore, a key-salvage-marker pointerKSM#n will also be referred to as a “KSM#n pointer”. The salvage markerSM#5, which has not yet been recorded, includes the location information(record) of the annulus #3, which is two annuli before. Furthermore, inthe salvage marker SM#5, the location information (record) of thesalvage marker SM#4 associated with the annulus #4, i.e., KSM(SM#4), isrecorded as a key-salvage-marker pointer. Since the salvage marker SM#5including the location information (record) of the recorded annulus #3has not yet been recorded, the location information (record) of theannulus #3 is recorded in the non-volatile-memory information.Furthermore, the location information (record) of the annulus #2 isdeleted from the non-volatile-memory information (since the locationinformation (record) of the annulus #2 has been recorded in the keysalvage marker SM#4). Furthermore, the location information of thesalvage marker SM#4 is recorded as a CSM in the non-volatile-memoryinformation.

FIG. 18 shows the state where the recording of data up to the AV data #6associated with the annulus #6 on the optical disc 111 has beenfinished, the salvage marker SM#7 and part of the AV data #7 associatedwith the annulus #7 have been recorded on the optical disc 111, and thesalvage marker SM#8 and part of the AV data #8 associated with theannulus #8 are going to be recorded on the optical disc 111.Furthermore, it is assumed that the salvage marker SM#7 associated withthe annulus #7 has been specified as a key salvage marker. In therecorded salvage marker SM#7 specified as a key salvage marker, aKSM(SM#7) pointer is recorded. The salvage marker SM#8, which has notyet been recorded, includes the location information (record) of theannulus #6, which is two annuli before. Furthermore, in the salvagemarker SM#8, the location information (record) of the salvage markerSM#7 associated with the annulus #7, i.e., KSM#7 pointer, is recorded asa key-salvage-marker pointer. Since the salvage marker SM#8 includingthe location information (record) of the recorded annulus #6 has not yetbeen recorded, the location information (record) of the annulus #6 isrecorded in the non-volatile-memory information. Furthermore, thelocation information (record) of the annulus #5 is deleted from thenon-volatile-memory information (since the location information (record)of the annulus #5 has been recorded in the key salvage marker SM#7).Furthermore, the location information of the salvage marker SM#7 isrecorded as a CSM in the non-volatile-memory information.

FIG. 19 shows the state where the recording of data up to the AV data #9associated with the annulus #9 on the optical disc 111 has beenfinished, the salvage marker SM#10 and part of the AV data #10associated with the annulus #10 have been recorded on the optical disc111, and the salvage marker SM#11 and part of the AV data #11 associatedwith the annulus #11 are going to be recorded on the optical disc 111.Furthermore, it is assumed that the salvage marker SM#10 associated withthe annulus #10 has been specified as a key salvage marker. In therecorded salvage marker SM#10 specified as a key salvage marker, aKSM#10 pointer is recorded. The salvage marker SM#11, which has not yetbeen recorded, includes the location information (record) of the annulus#9, which is two annuli before. Furthermore, in the salvage markerSM#11, the location information (record) of the salvage marker SM#10associated with the annulus #10, i.e., KSM#10 pointer, is recorded as akey-salvage-marker pointer. Since the salvage marker SM#11 including thelocation information (record) of the recorded annulus #9 has not yetbeen recorded, the location information (record) of the annulus #9 isrecorded in the non-volatile-memory information. Furthermore, thelocation information (record) of the annulus #8 is deleted from thenon-volatile-memory information (since the location information (record)of the annulus #8 has been recorded in the key salvage marker SM#10).Furthermore, the location information of the salvage marker SM#10 isrecorded as a CSM in the non-volatile-memory information.

When power supply is interrupted immediately after the state shown inFIG. 19, for example, due to detachment of the battery, data up to theAV data #9 associated with the annulus #9, and the salvage marker SM#10and part of the AV data #10 associated with the annulus #10 are recordedon the optical disk 111, as shown in FIG. 20. In the non-volatile-memoryinformation, the location information (record) of the annulus #9, a CSMrepresenting the position of the salvage marker SM#10, and the locationinformation (record) of the salvage markers SM#4, SM#7, and SM#10respectively associated with the annuli #4, #7, and #10 askey-salvage-marker pointers are recorded.

In the state shown in FIG. 20, data from the salvage marker SM#1associated with the annulus #1 to part of the AV data #10 associatedwith the annulus #10 has been recorded on the optical disc 111, but hasnot been reflected on the file system (management information).Accordingly, it is not possible to read the data under the currentstate. Thus, in order to allow reading of the data, a data restoringprocess described below is executed.

Next, a disc handling process including a data restoring process will bedescribed with reference to a flowchart shown in FIG. 21. The dischandling process is started when power supply to the recording andplayback apparatus 110 is started.

In step S101, the controller 120 waits until the optical disc 111 isloaded. When the optical disc 111 has been loaded, the process proceedsto step S102, in which the controller 120 mounts the file system (FS,i.e., management information). More specifically, the controller 120reads the file system (management information) from the optical disc111, and executes processing such as parsing.

In step S103, the controller 120 reads an XML (Extensible MarkupLanguage) file. More specifically, the controller 120 reads an XML fileobtained by the parsing in step S102.

In step S104, the controller 120 refers to the LVID of UDF. This can bedetermined by Res of the file system mounting. It is assumed herein thatthe file system (management information) is UDF. The LVID of UDFindicates whether the file system (management information) recorded onthe optical disc 111 has been normally closed. Thus, by referring to theLVID of UDF, it is possible to determine whether the file system hasbeen normally closed.

In step S105, the controller 120 determines whether a close flag hasbeen set to the LVID of UDF. When a close flag has been set, it isindicated that the file system (management information) has beennormally closed. When a close flag has not been set, e.g., when an openflag has been set, it is indicated that the file system (managementinformation) has not been closed normally. For example, when data fromthe salvage marker SM#1 associated with the annulus #1 to part of the AVdata #10 associated with the annulus #10 has been recorded on theoptical disc 111 but has not been reflected on the file system(management information), as shown in FIG. 20, it is considered that thefile system has not been closed normally. When it is determined in stepS105 that a close flag has been set to the LVID of UDF, the file systemhas been normally closed. Thus, the process is exited.

When it is determined in step S105 that a close flag has not been set tothe LVID of UDF, i.e., when the file system has not been closednormally, the process proceeds to step S106. When the file system hasnot been closed normally, it is indicated, for example, that a recordedprocess was previously interrupted on the optical disc and data shouldbe restored (i.e., data recorded before the interruption of therecording process should be registered as a file in the file system.

In the file system, file names associated with data recorded on theoptical disc 111, recording positions of the data on the optical disc111, and other data are registered. When a recording process wasinterrupted, the recording position on the optical disc 111 of data thatwas being recorded, a file name associated with the data that was beingrecorded, and other information are not registered in the file system.Thus, the recording area where data was recorded up to when therecording process was interrupted is registered in the file system as anempty area where data has not been recorded.

Thus, in step S106, the controller 120 checks whether thenon-volatile-memory information exists in the non-volatile memory 122.When it is determined that the non-volatile-memory information does notexist in the non-volatile memory 122, the process proceeds to step S110described later. When it is determined that the non-volatile-memoryinformation exists in the non-volatile memory 122, the process proceedsto step S107 described later.

In step S107, the controller 120 checks whether the non-volatile-memoryinformation is valid. More specifically, the controller 120 compares anindex ID recorded in the file system of the optical disc 111, whichserves identification information of the optical disc 111, with an indexID (FIG. 9) read from the non-volatile-memory information in thenon-volatile memory 122, thereby determining whether these index IDsmatch. When the recording process on the optical disc 111 wasinterrupted by another recording and playback apparatus that isdifferent from the recording and playback apparatus 110, it isdetermined that these index IDs do not match. Then, the process proceedsto step S110 described later. When the recording process on the opticaldisc 111 was interrupted by the recording and playback apparatus 110, itis determined that these index IDs match. Then, the process proceeds tostep S108.

In step S108, the controller 120 executes a quick salvage process. Inthe quick salvage process, the file system is updated based on thenon-volatile-memory information recorded in the non-volatile memory 122and salvage markers recorded on the optical disc 111. To simply describean example of the quick salvage process, the controller 120 sequentiallyreads key salvage markers from the optical disc 111 based onkey-salvage-marker pointers recorded in the non-volatile-memoryinformation, and updates the file system based on the annulus locationinformation (record) recorded in the key salvage markers and the annuluslocation information included in the non-volatile-memory information andnot yet recorded in SM on disc (the location information (record) of theannulus #9 in the example shown in FIG. 20).

The quick salvage process in step S108 will be described in detail withreference to a flowchart shown in FIG. 23.

In step S141, the salvage processor 134 of the controller 120sequentially reads key salvage markers from the optical disc 111 basedon key-salvage-marker pointers recorded in the non-volatile-memoryinformation.

For example, when the quick salvage process is started from the stateshown in FIG. 20, the salvage processor 134 of the controller 120 readsthe key salvage markers KSM#4, KSM#7, and KSM#10 from the optical disc111 based on the key-salvage-marker pointers (SM#4 pointer, SM#7pointer, and SM#10 pointer) in the non-volatile-memory information, asshown in FIG. 24.

Since the key salvage markers (KSM) are located separately, the spindlemotor 112 that rotates the optical disc 111 can employ CAV. In thiscase, all the key salvage markers can be read more quickly than in thecase of CLV.

In step S142, the salvage processor 134 of the controller 120 stores thekey salvage markers read in the volatile memory 121. In the exampleshown in FIG. 24, the key salvage markers KSM#4, KSM#7, and KSM#10(i.e., the salvage markers SM#4, SM#7, and SM#10) are stored in thevolatile memory 121.

In step S143, the salvage processor 134 obtains “annulus locationinformation not yet recorded in SM on disc” recorded in thenon-volatile-memory information. In the example shown in FIG. 24, thesalvage processor 134 obtains the location information (record) of theannulus #9 from the non-volatile-memory information.

In step S144, the salvage processor 134 stores the “annulus locationinformation not yet recorded in SM on disc” obtained in step S143 in thevolatile memory 121. In the example shown in the location information(record) of the annulus #9 is stored in the volatile memory 121.

In step S145, the salvage processor 134 restores the file system basedon the annulus location information included in the key salvage markersstored in the volatile memory 121 and the annulus location informationnot yet recorded in SM on disc.

In the case of the example shown in FIG. 24, the salvage processor 134restores the file system based on the location information (record) ofthe annuli #1 and #2 included in the key salvage marker KSM#4 (i.e., thesalvage marker SM#4 specified as a key salvage marker), the locationinformation (record) of the annuli #3 to #5 included in the key salvagemarker KSM#7, the location information (record) of the annuli #6 to #8included in the key salvage marker KSM#10, and based on the locationinformation (record) of the annuli #9 not yet recorded in SM on disc,stored in the volatile memory 121.

Although it is possible to read and restore the salvage marker #10 ofthe annulus #10, the salvage marker SM#10 is not particularly restoredsince it is generated for the restoration of the file system. However,the salvage marker SM#10 may also be restored.

In step S146, the salvage processor 134 generates a footer and a header.In step S147, the salvage processor 134 records the footer and theheader as indicated in the RT area in FIG. 25.

In step S148, the salvage processor 134 writes back the file systemrestored. Thus, the salvage markers and AV data of the annuli #1 to #9are reflected on the file system, as shown in FIG. 25. At this time, aclose flag is set in LVID of UDF, although not shown. That is, a flagindicating that the file system has been normally closed is set. Thefile system can be restored and updated in the manner described above.After step S145, the process is exited to return to step S108 shown inFIG. 21.

Since the quick salvage process is executed based on thenon-volatile-memory information in the non-volatile memory 122 as shownin FIG. 23, the file system can be restored and updated quickly. Thatis, it is possible to read data recorded on the optical disc 111.

Referring back to FIG. 21, after step S108, in step S109, the controller120 notifies the application (APL) of the salvage OK status and thecompletion of mounting. That is, the controller 120 notifies the APL ofthe completion of the salvage process (i.e., the file system has beenclosed normally) and the completion of the mounting (the mounting instep S102). The process is then exited.

On the other hand, when it is determined in step S106 that thenon-volatile-memory information does not exit, or when it is determinedin step S107 that the non-volatile-memory information is not valid, itis not possible to execute the quick salvage process. Then, the processproceeds to step S110.

In step S110, the controller 120 notifies the APL of the salvage NEEDstatus (the status indicating that a full salvage is to be executed) andthe completion of the mounting (the mounting in step S102).

In step S111, the controller 120 causes a display (not shown) to displaya message that prompts the user to determine whether or not to execute adata restoring process (a full salvage process). Then, in step S112, thecontroller 120 determines whether the user has performed an operationfor instructing the execution of the data restoring process (fullsalvage process). When it is determined that the user has performed anoperation for instructing the execution of the data restoring process(full salvage process), the process proceeds to step S113, in which thecontroller 120 receives a request for the full salvage process from theAPL.

In step S114, the controller 120 (the salvage-marker detector 133 andthe salvage processor 134) executes the full salvage process. In thefull salvage process, the file system is restored based on only theinformation recorded on the optical disc 111 without using thenon-volatile memory 122. The full salvage process is executed, forexample, when it is not possible to execute the quick salvage process bythe recording and playback apparatus 110 due to a failure of therecording and playback apparatus 110 and the file system is restored byanother recording and playback apparatus. That is, the full salvageprocess is executed when a disc ID corresponding to the disc ID of theoptical disc 111 is not recorded in the non-volatile-memory informationin the non-volatile memory 122 and the file system of the optical disc111 is to be restored.

To simply describe an example of the full salvage process, thecontroller 120 detects a last salvage marker that has been recorded laston the optical disc 111 from the optical disc 111, sequentially readskey salvage markers based on key-salvage-marker pointers recorded in thelast salvage marker, and updates the file system based on the locationinformation (record) of annuli recorded in the key salvage markers. Thefull salvage process will be described later in detail with reference toFIG. 26.

In the processes shown in FIGS. 21 and 22, the user is prompted todetermine whether data is to be restored (step S111 and step S112)before the full salvage process in step S114. This is because the timetaken for the full salvage process is longer compared with the quicksalvage process in step S108 described earlier. Obviously, however, theuser may be prompted to determine whether data is to be restored beforethe quick salvage process. Alternatively, after step S110, steps S111and S112 may be omitted so that the process directly proceeds to stepS113.

After step S114, the process proceeds to step S115, in which thecontroller 120 notifies the APL of the completion of the full salvageprocess. The process is then exited.

By the processes shown in FIGS. 21 and 22, it is possible to restorethat was being recorded even when the recording was not completednormally.

In the salvage markers SM#1 to SM#9, file data of non-real-time dataassociated with annuli up to the annulus #10 is recorded. Using thedata, the file data of non-real-time data associated with annuli up tothe annulus #10 can be recorded in the non-real-time area 11 (FIG. 1),and the non-real-time file data recorded can be reflected on the filesystem.

When it is determined in step S112 that an operation for not restoringdata has been performed so that the full salvage process in step S114 isnot executed, and the recording process is executed after that, the datanot restored (data that was not registered as files in the file system)is overwritten with new data. Thus, the data not restored is eventuallydeleted from the optical disc 111.

Next, the full salvage process in step S114 will be described in detailwith reference to a flowchart shown in FIG. 26.

In step S181, the salvage-marker detector 133 of the controller 120executes a last-salvage-marker detecting process. The last salvagemarker is a salvage marker that has been recorded last on the opticaldisc 111 in a recording process among data that has been recorded on theoptical disc 111 but has not been reflected on the file system. That is,the last salvage marker is the latest salvage markers among the salvagemarkers recorded on the optical disc 111, and corresponds to the salvagemarker represented by the current-salvage-marker pointer. In otherwords, when recording was not completed normally, the salvage-markerdetector 133 detects, as the last salvage marker, a salvage marker thatwas the current salvage marker at the time that the recording wasinterrupted. Since the non-volatile-memory information does not existand the current-salvage-marker pointer is not held, the last salvagemarker is detected without using the non-volatile-memory information.

An example of the last-salvage-marker detecting process in step S181will be described in detail with reference to a flowchart shown in FIG.27. In the example shown in FIG. 27, a last salvage marker is detectedby binary search.

Now, binary search will be described. In a sorted data sequence, first,target data (X) is compared with an element (m) in the middle of thedata sequence. When the target data (X) does not match the element (m),it is determined whether the target data (X) exists before or after themiddle of the data sequence based on the magnitude relationship betweenthe target data (X) and the element (m). For example, when the datasequence has been sorted in ascending order, the target data (X) existsbefore the middle if it is smaller than the element (m), while thetarget data (X) exits after the middle if it is larger than the element(m). Thus, the data sequence is divided in the middle, and the targetdata (X) is compared with a new middle element (m) in a segment wherethe target data (X) can exist. This operation is repeated until thetarget data (X) matches an element (m) or it is not possible to furtherdivide the data sequence. When it is not possible to further divide thedata sequence, it is determined that the target element was not found.When the target data (X) matches an element (m), it is determined thatthe target data (X) has been detected.

In step S201, the salvage-marker detector 133 refers to the file systemto check an empty area.

In step S202, the salvage-marker detector 133 performs seeking in thenegative direction by half the distance of the empty area. The negativedirection refers to the direction toward the inner side of the opticaldisc 111, and the positive direction refers to the direction toward theouter side of the optical disc 111.

In step S203, the salvage-marker detector 133 reads one annulus from theposition reached by the seeking. This is because salvage markers arerecorded on an annulus-by-annulus basis, and even when a salvage markeris recorded in the annulus, it is not possible to detect the salvagemarker without reading one annulus.

In step S204, the salvage-marker detector 133 determines whether a validsalvage marker has been detected. More specifically, the salvage-markerdetector 133 determines whether a valid salvage marker has been detectedby reading one annulus in step S203. For example, the salvage-markerdetector 133 determines that a valid salvage marker has been detectedwhen the number of times of circulating recording (refer to FIG. 8)recorded in the salvage marker detected is greater than the number oftimes of circulating recording recorded in the file system. Then, theprocess proceeds to step S206. On the other hand, the salvage-markerdetector 133 determines that a valid salvage marker has been detected,for example, when the number of times of circulating recording recordedin the salvage marker detected is not greater than the number of timesof circulating recording recorded in the file system or when no salvagemarker has been detected. Then, the process proceeds to step S205.

Since it is determined whether the salvage marker detected is validbased on the number of times of circulating recording, for example, evenif the date and time recorded on the optical disc 111 is incorrect dueto a timer failure of the recording and playback apparatus 110 or thelike, it is possible to determine whether the salvage marker detected isvalid more accurately.

The validity of a salvage marker may be determined based on a factorother than the number of times of circulating recorded. For example, thevalidity of a salvage marker may be determined based on the simplenumber of times of recording (the number of times of recording on theoptical disc 111 where circulating recording is not performed) or therecording date and time. When the validity of a salvage marker isdetermined based on the recording date and time, the salvage-markerdetector 133 compares the recording date and time (refer to FIG. 8)included in the salvage marker detected with the update date and time ofthe file system, and determines that a valid salvage marker has beendetected when the recording date and time (recording time information)included in the salvage marker is newer than the update date and time ofthe file system.

When it is determined in step S204 that a valid salvage marker has notbeen detected, in step S205, the salvage-marker detector 133 performsseeking in the negative direction from the current position by half thedistance of the previous seeking.

On the other hand, when it is determined in step S204 that a validsalvage marker has been detected, in step S206, the salvage-markerdetector 133 performs seeming in the positive direction from the currentposition by half the distance of the previous seeking.

After step S205 or step S206, the process proceeds to step S207, inwhich the salvage-marker detector 133 reads one annulus from theposition reached by the seeking.

In step S208, the salvage-marker detector 133 determines whether a validsalvage marker has been detected. More specifically, similarly to stepS204 described earlier, the salvage-marker detector 133 determineswhether a valid salvage marker has been detected in the data read instep S207. When it is determined in step S208 that a valid salvagemarker has not been detected, the process returns to step S205, andsubsequent steps are repeated. That is, in the second iteration of stepS205, the salvage-marker detector 133 again performs seeking in thenegative direction from the current position by half the distance of theprevious seeking, in step S207, reads one annulus from the positionreached by the seeking, and determines in step S208 whether a validsalvage marker has been detected. In other words, the salvage-markerdetector 133 repeats seeking in the negative direction by half thedistance of the previous seeking until a valid salvage marker isdetected.

When it is determined in step S208 that a valid salvage marker has beendetected, the process proceeds to step S209, in which the salvage-markerdetector 133 determines whether the valid salvage marker coincides withthe previously detected salvage marker. For example, when it isdetermined in step S204 that a valid salvage marker has been detectedand it is determined in step S209 that a valid salvage marker has beendetected, the salvage-marker detector 133 determines whether thepreviously detected salvage marker (detected in step S204 in this case)and the currently detected salvage marker (detected in step S208 in thiscase) are the same salvage marker. More specifically, it is determinedthat the valid salvage marker coincides with the previously detectedsalvage marker when the annulus of the previously detected salvagemarker coincides with the annulus of the currently detected salvagemarker, i.e., when the increment numbers (refer to FIG. 8) of these twosalvage markers coincide with each other. When no valid salvage markerhas been previously detected, it is determined that the valid salvagemarker does not coincide with the previously detected valid salvagemarker.

When it is determined in step S209 that the valid salvage marker doesnot coincide with the previously detected valid salvage marker, theprocess returns to step S206, and subsequent steps are repeated. Sincestep S209 is executed after step S208 results in YES, i.e., after avalid salvage marker has been detected. Thus, in step S206, thesalvage-marker detector 133 performs seeking in the positive directionfrom the current position by half the distance of the previous seeking.This is repeated until a valid salvage marker coincides with apreviously detected valid salvage marker.

When it is determined in step S209 that the valid salvage markercoincides with the previously detected valid salvage marker, the processproceeds to step S210. In step S210, the salvage-marker detector 133sets the coinciding valid salvage marker as a last salvage marker. Theprocess is then exited to return to step S181 in FIG. 26.

By the process shown in FIG. 27, a last salvage marker can be detected.Furthermore, since binary search is used to detect a last salvagemarker, a last salvage marker can be detected more efficiently.

Although binary search is used to detect a last salvage marker in theexample shown in FIG. 27, other searching methods may be used. Forexample, n-ary search (n is a natural number greater than or equal to2). Alternatively, for example, salvage markers may be sequentiallydetected by sequentially reading data from the beginning or the end ofan empty area, checking whether each of the salvage markers is a lastsalvage marker.

Next, the last-salvage-marker detecting process shown in FIG. 27 will bedescribed more specifically with reference to FIG. 28.

FIG. 28 shows data that is recorded on the optical disc 111 in a casewhere power supply was interrupted, for example, due to detachment ofthe battery, immediately after the sate shown in FIG. 19. This processis executed when the non-volatile-memory information is not recorded inthe non-volatile memory 122 (i.e., a full salvage process), so that asopposed to the case shown in FIG. 20, the non-volatile-memoryinformation is not held in this case (the non-volatile-memoryinformation is not shown in FIG. 28). As shown in FIG. 28, on theoptical disc 111, data up to the AV data #9 associated with the annulus“9 and the salvage marker #10 and part of AV data #10 associated withthe annulus #10 are recorded. In FIG. 28, the first tier represents datarecorded in the RT area, and the second tier represents a scaled downversion of the RT area in the first tier.

In step S201, the salvage-marker detector 133 refers to the file systemto recognize an area from a position P1 to a position P8 in FIG. 28 asan empty area. In step S202, the salvage-marker detector 133 performsseeking to a position P7, which is in the negative direction (leftwardas viewed in FIG. 28) by half the distance from the position P1 to theposition P8 forming the empty area. Then, in step S203, thesalvage-marker detector 133 reads one annulus from the position P7reached by the seeking. In step S204, the salvage-marker detector 133determines whether a valid salvage marker has been detected. Since avalid salvage marker has not been detected at the position P7, theprocess proceeds to step S205.

In step S205, the salvage-marker detector 133 performs seeking to aposition P6, which is in the negative direction (leftward in FIG. 28)from the current position P7 by half the distance of the previousseeking (i.e., the distance from the position P7 to the position P8). Instep S207, the salvage-marker detector 133 reads one annulus from theposition P6 reached by the seeking. In step S208, the salvage-markerdetector 133 determines whether a valid salvage marker has been detectedin the annulus read. Since a valid salvage marker has not been recordedat the position P6, the process returns to step S205.

In the second iteration of step S205, the salvage-marker detector 133performs seeking to a position P2, which is in the negative direction(leftward in FIG. 28) from the current position P6 by half the distanceof the previous seeking (i.e., the distance from the position P6 to theposition P7). In step S207, the salvage-marker detector 133 reads oneannulus from the position P2 reached by the seeking. In step S208, thesalvage-marker detector 133 determines whether a valid salvage markerhas been detected in the annulus read. Since a valid salvage marker hasbeen recorded at the position P2, the process proceeds to step S209.

In step S209, the salvage-marker detector 133 determines whether thevalid salvage marker detected at the position P2 (the salvage markerdetermined as valid in step S208) coincides with the previously detectedvalid salvage marker. In this case, no valid salvage marker has beenpreviously detected, so that step S209 results in NO. The process thenreturns to step S206.

Then, in step S206, the salvage-marker detector 133 performs seeking tothe position P3, which is in the positive direction (rightward in FIG.28) from the current position P2 by half the distance of the previousseeking (i.e., the distance from the position P2 to the position P6). Instep S207, the salvage-marker detector 133 reads one annulus from theposition P3 reached by the seeking. In step S208, the salvage-markerdetector 133 determines whether a valid salvage marker has beendetected. Since a valid salvage marker (SM#10) has been recorded at theposition P3, the process proceeds to step S209.

In step S209, the salvage-marker detector 133 determines whether thevalid salvage marker detected at the position P3 (i.e., the salvagemarker determined as valid in step S208) coincides with the previouslydetected valid salvage marker (i.e., the valid salvage marker detectedat the position P2). In this case, as shown in FIG. 28, the validsalvage marker detected at the position P3 (SM#10) does not coincidewith the valid salvage marker detected at the position P2, so that stepS209 results in NO. Then, the process returns to step S206.

Then, in step S206, the salvage-marker detector 133 performs seeking toa position P5, which is in the positive direction (rightward in FIG. 28)from the current position P3 by half the distance of the previousseeking (i.e., the distance from the position P2 to the position P3). Instep S207, the salvage-marker detector 133 reads one annulus from theposition P5 reached by the seeking. In step S208, the salvage-markerdetector 133 determines whether a valid salvage marker has been detectedin the annulus read. Since a valid salvage marker has not been recordedat the position P5, the process returns to step S205.

Then, in step S205, the salvage-marker detector 133 performs seeking toa position P4, which is in the negative direction (leftward in FIG. 28)from the current position P3 by half the distance of the previousseeking (i.e., the distance from the position P3 to the position P5). Instep S207, the salvage-marker detector 133 reads one annulus from theposition P4 reached by the seeking. In step S208, the salvage-markerdetector 133 determines whether a valid salvage marker has been detectedin the annulus read. Since a valid salvage marker (SM#10) has beenrecorded at the position P4, the process proceeds to step S209.

In step S209, the salvage-marker detector 133 determines whether thevalid salvage marker detected at the position P4 (SM#10) coincides withthe previously detected valid salvage marker (the valid salvage markerSM#10 detected at the position P3). In this case, as shown in FIG. 28,the valid salvage marker detected at the position P4 (SM#10) coincideswith the valid salvage marker detected at the position P3 (SM#10), sothat step S209 results in YES. Then, the process proceeds to step S210.

Then, in step S210, the salvage-marker detector 133 sets the validsalvage marker determined as coinciding in immediately preceding stepS209 as a last salvage marker. That is, the salvage-marker detector 133detects the salvage marker SM#10 represented by “Last_SM” in FIG. 28 asa last salvage marker. In this way, a last salvage marker can bedetected by the process shown in FIG. 27.

After the last-salvage-marker detecting process shown in FIG. 27, theprocess proceeds to step S182 shown in FIG. 26. In step S182, thesalvage processor 134 reads the last salvage marker detected by thesalvage-marker detector 133 in step S181. For example, in the salvagemarker SM#10 shown in FIG. 28, the KSM#4 pointer, the KSM#7 pointer, theKSM#10 pointer, and the location information (record) of the annuli #6to #9 are recorded. Thus, the salvage processor 134 reads the salvagemarker SM#10 including these pieces of data from the optical disc 111.

In step S183, the salvage processor 134 stores the last salvage markerread in the volatile memory 121. For example, in the volatile memory121, the data included in the last salvage marker is stored, as shown onthe first tier in FIG. 29. The last salvage marker includeskey-salvage-marker pointers and the location information (record) ofannuli up to two annuli before. In the example shown in FIG. 29,information of the salvage marker SM#10 (i.e., the KSM#4 pointer, theKSM#7 pointer, the KSM#10 pointer, and the location information of theannuli #6 to #9) is stored in the volatile memory 121.

In step S184, the salvage processor 134 sequentially reads key salvagemarkers from the optical disc 111 based on the key-salvage-markerpointers stored in the volatile memory 121. In the example shown in FIG.29, the salvage processor 134 reads the key salvage markers KSM#4,KSM#7, and KSM#10 from the optical disc 111 based on the SM#4 pointer,the SM#7 pointer, and the SM#10 pointer, which are key-salvage-markerpointers stored in the volatile memory 121.

At this time, since the key salvage markers (KSM) are disposedseparately, the non-volatile memory 122 for rotating the optical disc111 may employ CAV. In this case, all the key salvage markers can beread more quickly than in the case of CLV.

In step S185, the salvage processor 134 stores the key salvage markersread in the volatile memory 121. In the case of the example shown inFIG. 29, the salvage processor 134 stores the key salvage markers KSM#4,KSM#7, and KSM#10 (i.e., the salvage markers SM#4, SM#7, and SM#10) inthe volatile memory 121.

Through the process described above, the key salvage markers are storedin the volatile memory 121 under the control of the salvage processor134. In the example shown in FIG. 29, the location information (record)of the annuli #1 and #2 is included in the key salvage marker KSM#4, thelocation information (record) of the annuli #3 to #5 is included in thekey salvage marker KSM#7, the location information (record) of theannuli #6 to #8 is included in the key salvage marker KSM#10, and thelocation information (record) of the annuli #6 to #8 in the last salvagemarker SM#10, so that the location information (record) of the annuli #1to #9 is stored in the volatile memory 121. In the case of this example,the last salvage marker SM#10 itself coincides with the key salvagemarker KSM#10. In the case of non-coincidence, the location informationof annuli that is stored in the last salvage marker but is not includedin the key salvage marker is used (as will be described later indetail).

In step S186, the salvage processor 134 restores the file system basedon the annulus location information included in the key salvage markersstored in the volatile memory 121 and the annulus location informationincluded in the last salvage marker. In the case of the example shown inFIG. 29, the salvage processor 134 restores the file system based on thelocation information (record) of the annuli #1 and #2 included in thekey salvage marker KSM#4, the location information (record) of theannuli #3 to #5 included in the key salvage marker KSM#7, and thelocation information (record) of the annuli #6 to #8 included in the keysalvage marker KSM#10.

In step S187, the salvage processor 134 creates a footer and a header.In step S188, the salvage processor 134 records the footer and headergenerated, for example, as indicated in the RT area shown in FIG. 30.

In step S189, the salvage processor 134 writes back the restored filesystem. Thus, the salvage markers and AV data of the annuli #1 to #8 arereflected on the file system, as shown in FIG. 30. At this time, a closeflag is set to the LVID (not shown) of UDF. That is, a flag indicatingthat the file system has been normally closed is set. The file systemcan be restored and updated in the manner described above. After stepS189, the process is exited to return to step S114 shown in FIG. 22.

By the process shown in FIG. 26, it is possible to detect a last salvagemarker and to update the file system based on information recorded inthe last salvage marker. That is, it becomes possible to read datarecorded on the optical disc 111.

For example, when the salvage markers recorded on the optical disc 111(e.g., the salvage markers recorded in an area recognized as an emptyarea in the file system) are detected and sequentially read and storedand then the file system is updated based on the location information(record) of the annuli recorded in the respective salvage markers, allthe salvage markers are read, so that it is difficult to employ CAV forthe spindle motor 112. Thus, compared with the case where only keysalvage markers are read in step S184 shown in FIG. 26 or in step S141shown in FIG. 23 described earlier, it takes more time for reading.However, as described earlier in relation to step S141 shown in FIG. 23and step S184 shown in FIG. 26, since only key salvage markers are readfrom the optical disc 111, it takes less time compared with the casewhere all the salvage markers are read, so that the salvage process canbe executed quickly.

Furthermore, even when the non-volatile-memory information is notrecorded in the non-volatile memory 122 (i.e., when the quick salvageprocess is not allowed), a last salvage marker can be detected, so thatit is not needed to read all the salvage markers and it is possible toupdate the file system quickly. More specifically, by detecting a lastsalvage marker including key-salvage-marker pointers and locationinformation of annulus data recorded on the optical disc 111 (thelocation information of annuli from annuli whose location information isincluded in the immediately preceding key salvage marker to two annulibefore), the salvage processor 134 is allowed to sequentially read keysalvage markers based on key-salvage-marker pointers. Furthermore, thesalvage processor 134 is allowed to update the file system based on thelocation information of annulus data recorded on the optical disc 111,included in key salvage markers, and the location information of annulusdata recorded on the optical disc 111, included in the last salvagemarkers. Thus, it is not needed to read all the salvage markers, and itis possible to update the file system quickly.

The full salvage process shown in FIG. 26 takes a longer time comparedwith the quick salvage process shown in FIG. 23 by an amountcorresponding to the time for detecting a last salvage marker. However,compared with the case where all the salvage markers are detected, thefile system can be updated more quickly. That is, even when effectivenon-volatile-memory information is not recorded, the file system can beupdated more quickly than in the case where all the salvage markers aredetected. Furthermore, it is possible to quickly allow reading data fromthe optical disc 111.

In the example shown in FIGS. 20 to 30, the last salvage marker at thetime of interruption of power supply (i.e., the salvage marker that wasthe current salvage marker at the time of interruption of power supply)is a key salvage marker (KSM#10). Now, a case where the last salvagemarker at the time of interruption of power supply is not a key salvagemarker will be described with reference to FIGS. 31 to 36.

FIG. 31 shows the state where the recording of data up to the AV data#10 associated with the annulus #10 on the optical disc 111 has beencompleted, the salvage marker 11 and part of the AV data #11 associatedwith the annulus #11 have been recorded on the optical disc 111, and thesalvage marker SM#12 and the AV data #11 are going to be recorded on theoptical disc 111. In the salvage marker SM#12, which has not yet beenrecorded, the location information (record) of the annulus #10, which istwo annuli before, and the location information (record) of the salvagemarker SM#10 associated with the annulus #10 as a key-salvage-markerpointer, i.e., the KSM#10 pointer, are recorded. Since the salvagemarker SM#12 including the location information (record) of the recordedannulus #10 has not yet been recorded, the location information (record)of the annulus #10 is recorded in the non-volatile-memory information.Furthermore, the location information (record) of the annulus #9 isdeleted from the non-volatile-memory information. Furthermore, thelocation information of the salvage marker SM#11 is recorded as a CSM inthe non-volatile-memory information.

When power supply is interrupted, for example, due to detachment of thebattery, immediately after the state shown in FIG. 31, data up to the AVdata #10 associated with the annulus #10, and the salvage marker SM#11and part of the AV data #11 are recorded on the optical disc 111, andthe location information (record) of the annulus #10, the CSMrepresenting the position of the salvage marker SM#11, and the locationinformation (record) of the salvage markers SM#4, SM#7, and SM#10 askey-salvage-marker pointers are recorded in the non-volatile-memoryinformation, as shown in FIG. 32.

In the state shown in FIG. 32, data from the salvage marker SM#1associated with the annulus #1 to the part of the AV data #11 associatedwith the annulus #11 has been recorded on the optical disc 111 but hasnot been reflected on the file system (management information). Thus, itis not currently possible to read this data. In order to allow readingof this data, the disc handling process described earlier with referenceto FIG. 21 is executed. The description will be given in a simplifiedmanner by omitting steps that need not be particularly described.

When it is determined in step S107 shown in FIG. 21 that thenon-volatile-memory information is valid, the process proceeds to stepS108, in which the salvage processor 134 executes the quick salvageprocess shown in FIG. 23. In step S141 shown in FIG. 23, key salvagemarkers are read based on key-salvage-marker pointers recorded in thenon-volatile-memory information (KSM#4, KSM#7, and KSM#10) as shown inFIG. 33, and the file system is restored and written back based on thekey salvage markers read and the location information (record) of theannulus #10, i.e., “annulus location information not yet recorded in SMon disc), as shown in FIG. 34. Thus, it becomes possible to read AV dataof the annuli #1 to #10, recorded on the optical disc 111.

On the other hand, in the example shown in FIG. 32, data up to the AVdata associated with the annulus #10, and the salvage marker SM#11 andpart of the AV data #11 associated with the annulus #11 are recorded onthe optical disc 111, the location information (record) of the annulus#10, a CSM representing the position of the salvage marker SM#11, andthe location information (record) of the salvage markers SM#4, SM#7, andSM#10 as key-salvage-marker pointers respectively associated with theannuli #4, #7, and #10 are recorded in the non-volatile-memoryinformation, and the non-volatile-memory information is not valid.

In this case, i.e., when it is determined in step S107 shown in FIG. 21that the non-volatile-memory information is not valid and the user hasrequested restoration (i.e., when step S112 results in YES), the processproceeds to step S114, in which the salvage-marker detector 133 and thesalvage processor 134 execute the full salvage process described withreference to FIG. 26. The last salvage marker detected in step S181shown in FIG. 26 (i.e., the process shown in FIG. 27) is the salvagemarker SM#11 (coinciding with the salvage marker that was the currentsalvage marker (CSM) at the time of interruption of power supply in FIG.32). In step S182, the last salvage marker is read and stored. Morespecifically, the salvage marker SM#11 as the last salvage markerincludes the KSM#4 pointer, the KSM#7 pointer, the KSM#10 pointer, andthe location information (record) of the annulus #9, i.e., annulusinformation not yet recorded in SM on disc. Thus, as indicated by“volatile memory 121” in FIG. 35, the SM#4 pointer, the SM#7 pointer,the SM#10 pointer as key-salvage-marker pointers, and the locationinformation (record) of the annulus #9 as annulus location informationnot yet recorded in SM on disc are stored.

Then, in step S184, based on the key-salvage-marker pointers stored, thekey salvage markers KSM#4, KSM#7, and KSM#10 are read. In step S185,these key salvage markers are stored. Then, based on the locationinformation included in the key salvage markers KSM#4, KSM#7, and KSM#10(the location information of the annuli #1 to #8) and the locationinformation included in the last salvage marker SM#11 (the locationinformation of the annulus #9), the salvage processor 134 restores thefile system in step S186, and writes back the file system in step S189,as shown in FIG. 36. Thus, the file system can be updated as shown inFIG. 36, so that it becomes possible to read the AV data of the annuli#1 to #9, recorded on the optical disc 111.

As described above, when the last salvage marker is a key salvage marker(FIG. 29) and the non-volatile-memory information is not valid (when thefull salvage process is executed), the key salvage marker recorded lastcoincides with the last salvage marker, so that the file system can berestored based only on key salvage markers. In contrast, when the lastsalvage marker is not a key salvage marker (FIG. 35) and thenon-volatile-memory information is not valid (when the full salvageprocess is executed), the file system can be restored using “annuluslocation information (record) not yet recorded in SM on disc” recordedin the last salvage marker in addition to the key salvage markerrecorded last.

As described above, according to the embodiment of the presentinvention, it is possible to restore that was being recorded even whenthe recording was not completed normally.

The processes described above can be summarized as follows.

On the optical disc 111, a file system representing association betweenidentification information for identifying files and recording positionsof the file on the optical disc 111, data of a plurality of annuli(segment data) constituting the files, and salvage markers for therespective pieces of the plurality of segment data constituting each ofthe files, the salvage markers at least including location informationof annulus data recorded on the optical disc 111. When the data size ofa salvage marker has reached a predetermined upper limit, the salvagemarker is specified as a key salvage marker. In salvage markers recordedafter the salvage marker specified as the key salvage marker, locationinformation of the key salvage marker on the optical disc 111 (i.e., akey-salvage-marker pointer) is further included.

The salvage-marker detector 133 detects a last salvage marker, i.e., thesalvage marker recorded last during a recording process in a recordingarea in which data has been recorded on the optical disc 111 but has notbeen reflected on the file system (an empty area of the file system),and stores key-salvage-marker pointers included in the last salvagemarker and segment-data location information recorded on the opticaldisc 111 in the volatile memory 121. Based on the key-salvage-markerpointers stored in the volatile memory 121 and the segment-data locationinformation recorded on the optical disc 111, the salvage processor 134executes a salvage process on the basis of each piece of annulus dataconstituting files so that annulus data that has been recorded on theoptical disc 111 but has not been reflected on the file system isreflected on the file system.

Thus, even when recording was not completed normally, it is possible torestore data that was being recorded. Furthermore, by detecting a lastsalvage marker, the data can be restore more quickly than in the casewhere all the salvage markers are detected.

The above description has been given in the context of an example wherethe recording process, the restoration decision process, and the datarestoration process are executed by the single recording and playbackapparatus 110. Alternatively, for example, a recording apparatus thatexecutes the recording process, a salvage apparatus that executes therestoration decision process and the data restoration process, and aplayback apparatus for playing back data from an optical disc may beprovided separately.

That is, the recording process may be executed by a recording apparatusnot having a function for executing the restoration decision process andthe data restoration process or a function for playing back data from anoptical disc, and the restoration decision process and the datarestoration process may be executed by a salvage apparatus not having afunction for recording data on or playing back data from an opticaldisc.

The present invention can be applied to disc-shaped recording mediaother than optical discs, or other recording media that allow randomaccess (e.g., semiconductor memories). Furthermore, the presentinvention can be applied to recording of data on any type of recordingmedium as long as data is managed in the form of files.

Furthermore, although the above description has been given in thecontext of an example where content data such as audio data and videodata and the file system (management data for managing the content data)are recorded on the same recording medium, the present invention can beapplied to cases where content data and the file system (managementdata) are not recorded on the same recording medium. For example, in apackage medium including a disc medium (or a tape medium) and asemiconductor memory are included in a single cartridge, content datamay be recorded on the disc medium (or the tape medium) while recordingthe file system in the semiconductor memory. As another example, of twoapparatuses connected via a network, content data may be held in one ofthe two apparatuses while holding the file system in the otherapparatus. Obviously, the present invention can be applied to othercases where content data and the file system (management data) are notrecorded on the same recording medium.

The series of processes described above can be implemented either inhardware or in software. When the series of processes is implemented insoftware, programs constituting the software are installed on acomputer, and the programs are executed by the computer, whereby thefunctions of the recording and playback apparatus 110 described aboveare achieved.

The steps of the programs provided by the recording medium (programstorage medium) need not necessarily be executed in the orders describedherein, and may be executed in parallel or individually.

It should be understood by those skilled in the art that variousmodifications, combinations, sub-combinations and alterations may occurdepending on design requirements and other factors insofar as they arewithin the scope of the appended claims or the equivalents thereof.

1. A playback apparatus for playing back data from a recording mediumhaving recorded thereon a file system representing association betweenidentification information for identifying a file and a position wherethe file is recorded, a plurality of pieces of segment data constitutingthe file, and markers for the respective pieces of segment data, eachmarker that is recorded after a key marker specified in certain casesincluding location information of the key marker, the playback apparatuscomprising: detecting means for detecting a last marker in a recordingarea where data has been recorded on the recording medium but has notbeen reflected on the file system, the last marker being a marker thatis recorded at an end of the recording medium in a recording process;and restoration processing means for executing, for each of the piecesof segment data constituting the file, a restoration process ofreflecting on the file system segment data that has been recorded on therecording medium but has not been reflected on the file system, based onthe location information of the key marker and the location informationof segment data, these pieces of location information being included inthe last marker detected by the detecting means.
 2. The playbackapparatus according to claim 1, wherein the key marker is specified whenthe size of a marker has reached a predetermined upper limit.
 3. Theplayback apparatus according to claim 1, wherein the restorationprocessing means reads a marker specified as the key marker from therecording medium based on the location information of the key marker onthe recording medium, and executes the restoration process based on thelocation information of the segment data, included in the marker read,and based on the location information of the segment data, included inthe last marker.
 4. The playback apparatus according to claim 1, whereinthe detecting means detects the last marker by executing binary searchin the recording area where data has been recorded on the recordingmedium but has not been reflected on the file system.
 5. The playbackapparatus according to claim 1, wherein each of the markers includes afirst number of times representing the number of times of rewriting in arecording area where the marker is recorded on the recording medium, andwherein when a marker is detected in the recording area where data hasbeen recorded on the recording medium but has not been reflected on thefile system, the detecting means determines whether the marker is thelast marker based on the first number of times included in the markerand a second number of times representing the number of times ofrewriting in the recording area where the marker is recorded on therecording medium, the second number of times having been reflected onthe file system.
 6. The playback apparatus according to claim 1, whereineach of the markers includes first date and time informationcorresponding to a date and time of recording of the marker on therecording medium, and wherein when a marker is detected in the recordingarea where data has been recorded on the recording medium but has notbeen reflected on the file system, the detecting means determineswhether the marker is the last marker based on the first date and timeinformation included in the marker and second date and time informationcorresponding to a date and time of updating of the file system.
 7. Theplayback apparatus according to claim 1, wherein each of the markersincludes location information of the associated segment data recorded onthe recording medium.
 8. A playback method for playing back data from arecording medium having recorded thereon a file system representingassociation between identification information for identifying a fileand a position where the file is recorded, a plurality of pieces ofsegment data constituting the file, and markers for the respectivepieces of segment data, each marker that is recorded after a key markerspecified in certain cases including location information of the keymarker, the playback method comprising the steps of: detecting a lastmarker in a recording area where data has been recorded on the recordingmedium but has not been reflected on the file system, the last markerbeing a marker that is recorded at an end of the recording medium in arecording process; and executing, for each of the pieces of segment dataconstituting the file, a restoration process of reflecting on the filesystem segment data that has been recorded on the recording medium buthas not been reflected on the file system, based on the locationinformation of the key marker and the location information of segmentdata, these pieces of location information being included in the lastmarker detected.
 9. A computer readable medium encoded with computerexecutable instructions for allowing a computer to execute a process ofplaying back data from a recording medium having recorded thereon a filesystem representing association between identification information foridentifying a file and a position where the file is recorded, aplurality of pieces of segment data constituting the file, and markersfor the respective pieces of segment data, each marker that is recordedafter a key marker specified in certain cases including locationinformation of the key marker, the process comprising the steps of:detecting a last marker in a recording area where data has been recordedon the recording medium but has not been reflected on the file system,the last marker being a marker that is recorded at an end of therecording medium in a recording process; and executing, for each of thepieces of segment data constituting the file, a restoration process ofreflecting on the file system segment data that has been recorded on therecording medium but has not been reflected on the file system, based onthe location information of the key marker and the location informationof segment data, these pieces of location information being included inthe last marker detected.
 10. A playback apparatus for playing back datafrom a recording medium having recorded thereon a file systemrepresenting association between identification information foridentifying a file and a recording position of the file on the recordingmedium, a plurality of pieces of segment data constituting the file, andmarkers for the respective pieces of segment data, each of the markersat least including location information of the associated segment datarecorded on the recording medium, each of the markers being specified asa key marker when the size of the marker has reached a predeterminedupper limit, and each marker that is recorded after the marker specifiedas the key marker further including location information of the keymarker on the recording medium, the playback apparatus comprising:detecting means for detecting a last marker in a recording area wheredata has been recorded on the recording medium but has not beenreflected on the file system, the last marker being a marker recordedlast on the recording medium in a recording process; storage means forstoring the location information of the key marker on the recordingmedium and the location information of segment data recorded on therecording medium, these pieces of location information being included inthe last marker detected by the detecting means; and salvage means forexecuting, for each of the pieces of segment data constituting the file,a salvage process of reflecting on the file system segment data that hasbeen recorded on the recording medium but has not been reflected on thefile system, based on the location information of the key marker on therecording medium and the location information of the segment datarecorded on the recording medium, these pieces of location informationhaving been stored in the storage means.
 11. A playback apparatus forplaying back data from a recording medium having recorded thereon a filesystem representing association between identification information foridentifying a file and a position where the file is recorded, aplurality of pieces of segment data constituting the file, and markersfor the respective pieces of segment data, each marker that is recordedafter a key marker specified in certain cases including locationinformation of the key marker, the playback apparatus comprising: adetector configured to detect a last marker in a recording area wheredata has been recorded on the recording medium but has not beenreflected on the file system, the last marker being a marker that isrecorded at an end of the recording medium in a recording process; and arestoration processor configured to execute, for each of the pieces ofsegment data constituting the file, a restoration process of reflectingon the file system segment data that has been recorded on the recordingmedium but has not been reflected on the file system, based on thelocation information of the key marker and the location information ofsegment data, these pieces of location information being included in thelast marker detected by the detector.
 12. A playback apparatus forplaying back data from a recording medium having recorded thereon a filesystem representing association between identification information foridentifying a file and a recording position of the file on the recordingmedium, a plurality of pieces of segment data constituting the file, andmarkers for the respective pieces of segment data, each of the markersat least including location information of the associated segment datarecorded on the recording medium, each of the markers being specified asa key marker when the size of the marker has reached a predeterminedupper limit, and each marker that is recorded after the marker specifiedas the key marker further including location information of the keymarker on the recording medium, the playback apparatus comprising: adetector configured to detect a last marker in a recording area wheredata has been recorded on the recording medium but has not beenreflected on the file system, the last marker being a marker recordedlast on the recording medium in a recording process; a storage unitconfigured to store the location information of the key marker on therecording medium and the location information of segment data recordedon the recording medium, these pieces of location information beingincluded in the last marker detected by the detector; and a salvage unitconfigured to execute, for each of the pieces of segment dataconstituting the file, a salvage process of reflecting on the filesystem segment data that has been recorded on the recording medium buthas not been reflected on the file system, based on the locationinformation of the key marker on the recording medium and the locationinformation of the segment data recorded on the recording medium, thesepieces of location information having been stored in the storage unit.